Talk:Random-access memory/Archive 1

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Archive 1

Questions concerning memory

When you refer to the layout of the pc memory, do you mean the internal memory(RAM) or all memory together(ROM)? Has logical adressing in real mode something to do with virtual addressing? Or are these types two different things? --Anonymous


When we talk about the amount of memory in a PC, we always refer to the RAM. The size of the ROM (BIOS) is often not known exactly, and it's measured in kbytes, so it doesn't make sense to compare it to RAMs. As far as addressing is concerned, they're completely different. Real mode addressing is a bit weird, you need memory managers to access the areas above 640k. That's why you have to use HIMEM.SYS (or sometimes EMM386.EXE or QEMM) to make HMA, UMB accessible in DOS. Virtual addressing is available only in protected mode, in which every modern operating system runs. In this mode, the whole accessible memory can be seen as one huge block. Of course, the CPU still sees the physical addresses only, therefore the kernel has to do virtual->real and real->virtual address space transformations for every application. --Niggurath 23:45, 13 October 2005 (UTC)y

What about adding info about 6116 Static Rams, and 4116 Mostek under intel 2116 4164 41256 and add model numbers for alot of other chips .. Also number of pins and Voltages ie 4116 12v,+-5v I pain in the arse to use - let me know if anyone has a problem with me adding this information. pinouts etc VladMaster99

Buffered, registered and ECC/parity RAM

Note: I moved this section from the article over here; I felt its technical contents weren't well enough explained. --Wernher 05:02, 24 October 2005 (UTC)

  • Buffered vs unbuffered: Buffered RAM adds a buffer between the memory chips and the memory controller to reduce the load on their signal lines. The controller sees only a single load - the buffer - rather than several memory chips.
  • Registered vs unregistered: Registered RAM stores the states of the data and address lines before applying them to the memory array. This reduces synchronisation errors, but adds a 1-cycle latency to transfers to the module.
  • ECC and parity: Normal RAM has 8-bits per byte on the chip. Parity adds an extra bit (making it 9-bits per byte) to add some primitive checking for single-bit errors, and works in a similar way to parity checking on serial transfers (e.g. with even parity, the bit is set to make the total of the bits even. If it is odd that means there is an error). ECC also uses a 9-bit-per-byte system, but uses a different system that enables it to detect and correct single bit errors, and detect 2-bit errors.

The 'random' part

The explanation of random vs sequential access seemed to say RAM chips random, everything else not, including disks. Modern disks and DVDs are random access, though they're not exactly addressable in the way a RAM chip is. But stepper motors, sectors and FATs make disks nearly as addressable, not like a tape that has to run entirely past the head to read a location. Hope I'm not missing something, 'cause I reworked some of that explanation. DavidH 22:05, 21 December 2005 (UTC)

Rotating storage devices (hard disks, DVDs, etc) are not random access memory devices, despite the occasional use of the term "random access" in connection with them (e.g. the first computer with a disk was RAMAC, for "Random Access Method of Accounting and Control").
Rotating storage does not meet the "defining characteristic of RAM" mentioned in the Overview - that the time needed to access memory locations does not vary significantly with location. Disk access does vary substantially: First, reading data on the same track which follows closely data just having been read is very much faster than reading data which closely preceeds data just having been read. The time needed is bounded by the time for the disk to rotate, but it does vary quite significantly. Second, the time needed for data on a distant cylinder is substantially more than for data on the same cylinder, and varies by distance.
Disks are sequential in two dimensions (rotation and head movement). This makes it faster to get to data than in one-dimensional sequential devices like tapes. It's like getting somewhere in a city with a grid of streets as opposed to a "strip" city which is spread along a single road. But still, most locations are not "next door" in a rotating device like they are in a RAM device. -R. S. Shaw 07:29, 22 December 2005 (UTC)
All true. Also, the smallest addressable unit is the sector. Individual bytes are only accessible serially. --Heron 14:56, 22 December 2005 (UTC)
The smallest addressable unit thing isn't a big issue in this semantic context; the 8-bit memory word common in microcomputers today wasn't so common a few decades back and really is largely attributable to the S/360 architecture. Frankly, the size of a memory word is somewhat arbitrary and the only reasons we don't often see larger (or smaller) memory units are compatibility and common memory utilization. The latter has really changed a good bit in recent years, to the point that in many modern applications a larger memory unit does make more sense. However, this is usually outweighed by the low costs of standard forms of RAM. In addition, pipelining and prediction in memory controllers as well as the function of cache largely make up for the minor penalties inflicted where a larger memory unit would be preferable. In like manner, sector sizes in hard drives are largely a matter of compatibility and standardization, not necessarily any technical concern.
In simple terms, smallest/largest addressable unit in a storage device has no bearing on whether or not it can be considered "random access" or not. There could very well be [A-Z]*-[SD]*RAM that is organized into 32-bit addressable units, and there could very well be non-random access devices like hard drives that DO use an 8-bit addressable unit. -- uberpenguin 18:28, 22 December 2005 (UTC)
I should have stated that I'm not talking about the Uber-geek definition of random access, I'm talking about real-world definitions for regular folks. In other words, cassette tape--definitely not random access; CD--pretty much so. You can't hide the fact that a DVD or hard drive is almost completely addressable and a few ms differences in access time makes most modern hard drives and optical media "random access" to a much greater extent than a tape that can only be read completely in sequence. If the article just says chips are random-access and everything else is not, it will obscure the reality of modern storage devices over a technicality. In other words, I support saying that modern disks and DVDs are practically random-access, though not in the very strict sense as for memory circuits.

I remember magnetic tape storage that was NOT random access, and to imply that modern mass storage is as crippled as the old sequential-access tapes seems really misleading. DavidH 01:21, 23 December 2005 (UTC)

Ah, but I am loathe to point out that it is the 'ueber-geeks' that generally set the terminology definitions. From the lay man's view, a tape could be considered "random access." I mean, why not? You can seek to any point on the tape at will... You absolutely don't have to read everything between point A and point B on a tape just to read point B (though everything between those points flys by the read head). What's the huge difference from a hard drive? Hard drives are simply two-dimensional rather than one-dimensional; you happen to pass fewer sectors on the way from point A to point B, but you still have to pass over data you don't care about.
When it comes down to it, though, we aren't talking about what the term "random access" could apply to, we are talking about how the term "random access memory" is used by people in the industry. It's pretty clear that your typical engineer/programmer never has a hard disk in mind when he mentions RAM, and that is what the article should reflect. I would liken this whole discussion to someone making the assertation that a DSP qualifies as a CPU simply because it 'processes data' and is 'central' to many applications. Just because a DSP somewhat fits the words use

So, instead of a dedicated page, we have 1 stub and two sections all talking about the same thing? That's l530?s=books&v=glance&n=283155 0142001783] p. 178—ROM & RAM:


[1] In the spirit of viewing the mind in terms of computer-like operations, some cognitive scientists like Tim Shallice and Phillip Johnson-Laird have referred to executive functions as supervisory or operating system functions. A computer operating system is responsible for controlling the flow of information processing, moving information from permanent memory (ROM) to a central processing unit with active memory (RAM), scheduling tasks to be preformed using the active memory, and so on. Similarly, executive functions are involved in the constant updating of temporary memory, selecting which specialized systems to work with (pay attention to) at the moment, and then moving relevant information into the workspace from long-storage by retrieving specific memories or activating schemata pertinent to the immediate situation. Through executive functions, specialized systems are also directed to attend to certain specific stimuli and to ignore others, depending on what working memory is working on. In complex tasks involving multiple kinds of mental activities, executive functions plan the sequence of mental steps and schedule the participation of the different activities, switching the focus of attention between activities as needed {interrupts}. Executive functions are crucially involved in decision-making, allowing you to choose between different courses of action given what is happening in the present, what you know about such situations, and what you can expect to happen if you do different things in this particular situation. Executive functions, in short, make practical thinking and reasoning possible.
[2] The executive represents a powerful mental capacity, but is not all-powerful. Like the workspace, it has its limits. It basically can do one or at most a few things at a time. This is why you forget a phone number if you are distracted while dialing. With practice and training, we can learn to divide our attention between two mental tasks simultaneously, but only with difficulty. In this sense, the executive is more like an old-fashioned DOS operating system that can only run one program at a time than like a multitasking Windows operating system that can concurrently run word processing, spreadsheet, e-mail, calendar, and other programs.
[3] ..... If the executive has to work on multiple unrelated goals at the same time, however, the system begins to fall apart, especially if the goals conflict with one another. An easy way to stress people is to make them do too much at once {computers crash, people have nervous breakdowns}. Planning, decision-making, and other aspects of mental life suffer when the executive is overloaded.

Yesselman 01:33, 21 January 2006 (UTC)

RAM corruption section

I removed a strange section about the corruption of ram due to buffer overflows. Many of the claims here seemed very strange. I'll leave it here in case there is some useful information there.

== Corrupted Ram ==
Ram can be corrupted by static electricity, magnetic fields, and buffer overflows.
Even preforming full software recoverys will not correct the issue, and software will often
crash or have errors that can't be identified. The problem is such an issue that it is illegal
to expiriment with buffer overflows on your own computer.
You're completely justified in removing it. No explanation is required. -- uberpenguin 18:26, 19 December 2005 (UTC)
Agree. SR - RE 18:38, 2 February 2006 (UTC)

VRAM detail conflict

On this page, you refer to VRAM as gaining popularity, but on the DRAM page, it says that VRAM is actually going obsolete. Which is right?

edit - Preliminary research seems to agree with the VRAM gaining popularity as a new technology theory. Will leave it to the usual crowd here to fix either this article or the other one.

Wahming 18:57, 8 February 2006 (UTC)

RAM Timing

Could anyone who knows anything about what timing is and how it works add this to the page? --SheeEttin 20:05, 28 April 2006 (UTC)

You're probably looking for information related to SDRAM, not RAM in general. -- uberpenguin @ 2006-04-29 03:16Z 03:16, 29 April 2006 (UTC)


Well, it'd be nice to have a mention; but yes, it is covered in SDRAM. --SheeEttin 15:18, 29 April 2006 (UTC)

missing information

This article is missing info on the speeds of RAM such as PC100 or PC133, and also info on DDR, DIMM, etc. MarioV 22:11, 8 June 2006 (UTC)

All of that information involves in articles about SDRAM, not RAM in general. -- uberpenguin @ 2006-06-08 22:17Z

Vacuum tube

Article says that Early vacuum tube-based systems behaved much like modern RAM

can someone elaborate this???


↑Who wrote this? Anyway yes will someone please elaborate on this it sounds interesting! Caleb09 20:34, 27 August 2006 (UTC)

This article by geeks, for geeks

This articles stinks. It assumes a huge prior knowledge of computer hardware. Will someone who understands the article please go through and make it accessible to laypeople by adding explanations and definitions for *all* of the computer-specific terms and concepts used?

This is what {{technical}} is for, and as far as I can see, all terms/concepts are explained in the article or intra-WP linked. — SheeEttin {T/C} 20:30, 18 July 2006 (UTC)

↑"No, that's Slashdot silly" lol xD Caleb09 20:36, 27 August 2006 (UTC)

I agree. That's why I quit being a member of Wikipedia. It went away from its layperson ideals.

RAM ≠ DRAM

SRAM, not DRAM, was the original type of semiconductor RAM, this should at least be mentioned.

As it stands now, this article is too personal computer centric, especially in the introduction. This kind of article certainly has its place, but a proper name would be "working memory", "main memory", "memory module", or something like that. The term "RAM" is a far more general concept, and deserves a well written article of its own.

/HenkeB 01:17, 1 November 2006 (UTC)

Quite so. I'd do it myself if I weren't occupied with other things. Unfortunately it's impossible to keep articles like this from declining into PC-centric messes unless you're willing to devote the time necessary to totally rewrite and defend it. -- mattb @ 2006-11-01T03:09Z
I'm not sure a total rewrite would be necessary. I agree, however, that defending articles is extremely time consuming (and can be psychologically exhausting as well). Maybe one could split the article into two separate ones -- one PC-oriented text, named main memory or similar, the other, more general one, named random access memory? Maybe that wouldn't be so hard to defend? /HenkeB 11:31, 2 November 2006 (UTC)
Heh... We already have an article called computer storage that should theoretically cover the main memory topic as it applies to computers in particular (it also needs work, though). Who knows... Once I finish rewriting Computer, I may turn my attention to some storage and memory hardware related articles. -- mattb @ 2006-11-02T17:29Z
This computer storage seems to be very generally computer oriented, at a system level. A more shallow, PC-oriented, article covering DDR, DDR2 memory sticks/modules, and such, is also fully relevant (given a proper name). However, I assume you agree the word RAM also strongly associates to electronics, single components, and implementation technology (as opposed to computer systems). Such an article on random access memory could be quite small, as most details are already covered in the fine DRAM, SRAM, ROM, FLASH, etc articles. /HenkeB 04:48, 3 November 2006 (UTC)

Legibility second paragraph

Folks, the second paragraph of the article got changed substantially this month. (After I had added it a few months ago.) Before Jan 6, it read:

It costs practically the same time to access any piece of data stored in a RAM chip. In contrast, disks and the like need a short time to retrieve a piece of data if it happens to be close to the current position of the read head, and a long time if the data is far away and the head needs to be repositioned considerably.

After several edits, it now reads:

The word "random" refers to the fact that any piece of data can be returned quickly, and in a constant time, regardless of its physical location and whether or not it is related to the previous piece of data. This contrasts with storage mechanisms such as tapes, magnetic disks and optical disks, which rely on the physical movement of the recording medium or a reading head. In these devices, the movement takes longer than the data transfer, and the retrieval time varies depending on the physical location of the next item.

Imho, that was not a good move. Precision wasn't enhanced, and no facts were added except for mentioning tapes and optical disks (which are marginal to the topic). Yet the paragraph became longer and lost clarity: The new version is too abstract and uses too much technical mumbo-jumbo -- e.g., why say "constant time" when you can say "the same time"?

The edits just added pointless complexity and made the paragraph more difficult to read, especially for laypeople. That's inappropriate for the lead section, and I'd recommend going back to the pre-Jan-6 version. --193.99.145.162 17:13, 18 January 2007 (UTC)

I have to agree that the wordier version is less appropriate than the shorter, earlier version. I favor changing it back, perhaps with some slight changes as in this version:
It takes about the same amount of time to access any piece of data stored in a RAM chip. In contrast, disks and the like need a longer time to retrieve a piece of data that is far away from the read head than if the desired data happens to be close to the current position of the read head.
-R. S. Shaw 22:20, 18 January 2007 (UTC)

Quick Expert Input

Can we get someone to label the image at the bottom with the form factor for each type of ram featured in the picture? Just toss it in Paint. I'd do it, but I'd get it wrong.Bmunden 21:22, 2 February 2007 (UTC)

Move DRAM info?

Should the section on DRAM Packaging be moved to the DRAM article? It seems to me that details about a particular type of RAM should not be included in this article, but should be in the article on that type of RAM. HeirloomGardener 19:11, 18 May 2007 (UTC)

Definition of "random access"

The article says:

The word "random" refers to the fact that any piece of data can be returned quickly, and in a constant time ...

The word "random" only refers to the fact that any word can be accessed in constant time. That fact that it can be accessed "quickly" is of no consequence.

I agree. "Quickly" is too subjective. (How quick?) HeirloomGardener 19:15, 18 May 2007 (UTC)

RAM photo

the VAX RAM photo is very pretty but very unrepresentative. how about a picture of RAM vaguely resembling something in wide use? Aaronbrick 05:10, 23 March 2006 (UTC)

Not true. VAXen were extremely common at one time, and it would be a serious error to inflict recentism on this article by removing it simply because it's no longer in use. -- uberpenguin @ 2006-04-29 03:19Z

Plus it's totally old school ;) Caleb09 20:35, 27 August 2006 (UTC)

I assume you are referring to Wikipedia:recentism? --75.37.227.177 04:10, 31 July 2007 (UTC)

Acronyms, their meanings and uses, level of expertise needed to understand article

I've got a couple of comments and suggestions I'd like to verify with other contributors here... Here they are:

  1. Article should start with an explanation that is useful for most people, especially for those who are not technical. It does not. For example, although that is incorrect, most people think of Primary storage (or "primary memory" or "working" or "operating") when they say RAM. While it is utterly useful that primary storage is RAM, it is not technically required. Furthermore, operating memory must also be other characteristics that RAM in itself does not describe.
  2. Article does point out what RAM stands for - Random Access Memory and touches to the inconsistency between true meaning and common use, but it stops short. For example, ROM and RAM are not mutually exclusive. For example, firmware of most computers is, in fact, both ROM (in that it can only be read) and RAM (in that it is random-accessible). Common use, of course, somehow implies that RAM is read/write and not ROM and, based on that, that ROM can not be RAM (because it can not be written to).
  3. No direct part of RAM implies that the content is lost without power. The fact that memory is randomly accessible (RAM) has nothing to do with whether it retains its content when power is lost.
  4. Same would be true for ROM, too, without a simple logical conclusion: if ROM can not be written to and looses the content with power loss then it is almost by definition empty, as lost content can not be (re)written to it. If you think about it, ROM does not exist - Write Once Read Many (WORM) does, because even ROM has to get its content from somewhere - once. For ROMs, this is assumed to be manufacturing process and not writing, which may get away with the logical issue. But, if you believe that it does, then ROMs can also loose the content when power is disconnected.... "this message will self-destruct in ..." ... all you need to recover it is to (re)manufacture the new ROM and put it in...
  5. Most people seem to differentiate between what they call RAM (actually thinking of Primary storage) and what they call Cache. Yet, I have yet to find such a modern device in which either primary storage or cache is not, in fact, random-accessible memory. Typically the difference is between dynamic and static RAM and, sometimes, the term 'Cache' includes the controller, not just the memory...
  6. Article mentions that "Flash memory" is a ROM/RAM hybrid. This is incorrect. Depending on the details of flash memory (is it addressable in blocks only or not) and random access (does it accept block access only), flash memory is RAM (or not). However, the whole purpose of flash is for it to not be ROM (it actually can be written to) and that it does not require power to be supplied to retain content. The fact that it does not need power to retain content does not make it a ROM. It is just possibly a shared characteristic between the ROM and flash, but ROM indicates a limitation (reading only) that does not apply to flash memory. The only reason why people are confusing flash and ROM is the incorrect assumption that ROM really only means "does not loose content..."

Enough comments from me now... anyone has anything to add? --Aleksandar Šušnjar 21:01, 12 February 2007 (UTC)


Noone interested enough to respond?

Here are the two current introductory paragraphs:

Random access memory (usually known by its acronym, RAM) is a type of data store used in computers. It takes the form of integrated circuits that allow the stored data to be accessed in any order — that is, at random and without the physical movement of the storage medium or a physical reading head.

The word "random" refers to the fact that any piece of data can be returned quickly, and in a constant time, regardless of its physical location and whether or not it is related to the previous piece of data. This contrasts with storage mechanisms such as tapes, magnetic disks and optical disks, which rely on the physical movement of the recording medium or a reading head. In these devices, the movement takes longer than the data transfer, and the retrieval time varies depending on the physical location of the next item.


I propose a change such as:

Random access memory (usually known by its acronym, RAM) is a type of data store used in computers. The term is colloquially used to specifically refer to primary (working) memory of computers and their parts, but the definition of RAM is much more generic than that.

The word "random" refers to the fact that any piece of data can be accessed (read or written, returned or stored) quickly, and in a relatively constant time, regardless of its physical location and whether or not it is related to the previous piece of data. This contrasts with storage mechanisms such as tapes, magnetic disks and optical disks, which rely on the physical movement of the recording medium or a reading head. In these devices, the movement takes longer than the data transfer, and the retrieval time varies depending on the physical location of the next item.


I also propose to have a section on coloquial use, that would have something like:

Term "RAM" is coloquially used as a memory that is not read-only and, therefore, contrasting the Read-Only Memory (ROM). Traditionally computers have some firmware stored in non-volatile ROMs and have separate working memory. While both are generally randomly accessible memories (RAM), the latter one is not read-only (ROM) as data can be written to it, not only read. This caused the primary memory to typically be called RAM. Same tradition caused generally accepted belief that RAMs are volatile (because ROMs are assumed not to be). Neither of the above is correct. The term "RAM" specifically refers to the style of addressing and accessing memory and not to its volatility or read/write capabilities.

The term is sometimes also used for the kind of memory that may or may not fit the definition of random access, depending on how strictly the definition is followed. For example, DVD-RAM indicates that it is RAM, because the drive can access any sector requested automatically. However, while doing so its reading head does pass over other data. Furthermore, some historical memories such as drum and delay line memory were considered randomly accessible because they hid their physically sequential nature with dedicated circuitry. That way even fully sequential tapes could be made randomly accessible.

--Aleksandar Šušnjar 04:03, 14 February 2007 (UTC)

I think you may be trying to put too fine a point on a term that is commonly used to mean many things. However, I wouldn't particularly object to your proposed changes. Give it a little time to allow others to comment, though. -- mattb @ 2007-02-14T04:13Z

85.66.109.142 19:26, 4 October 2007 (UTC)Thomas Kiss 21:22, 4 October 2007 (GMT+1) There is something important not stated in the original article. The term ROM means that the memory is read-only, but it does not say that this is from the processors point of view. You can write the most of the ROM memories with the aporpriate hardware. Iz is only unwriteable by the processor itself.

Disks and drums sequential?

The first paragraph states that disks and drums are sequential memory, but is this true? Tapes are, but the head of a disk can move between tracks, so it's only partially sequential. I suppose this is nitpicking, but are disks generally considered sequential memory devices? DirkvdM 08:41, 15 October 2005 (UTC)

They're still sequential, but with a bit of parallelism to improve efficiency. If you have two disk sectors A and B sitting adjacent to one another on the same cylinder, you can access sector B and then you have to wait for the disk to complete one revolution before you can access sector A. If on the other hand you read sector A and B in that order, they could be read sequentially and without the one-revolution delay.

Another way of looking at it is that, given enough speed, a sequential device approximates a random access device. The file system permits application software to treat the disk drive as if it were a random access device. Use of buffers within the application software and the file system provide further layers of random access, and to complicate things even further paged virtual memory computer architecture provides a means of using the disk drive to simulate a random access memory much larger than the computer possesses physical RAM. --Tony SidawayTalk 09:16, 15 October 2005 (UTC)

Yeah, I was already aware of most of that. But my question was if a disk is generally (or even 'officially', if there is such a thing) regarded as sequential. But to continue with your thoughts. Suppose we don't cheat by using a buffer and give all three devices the same 'burst-speed' (is that the right word? I mean speed of continuous access). Then of course in everyday use the chip would be fastest and the tape slowest, with the disk somewhere in between. But it would be a whole lot closer to the chip than to the tape (for it to be exactly in the middle you'd have to be reading some big files (and unfragmented when using msWindows)). So in that sense it would seem unfair to call it sequential. Then again, this is not a speed contest. It's about the principle by which it works and that is only partially sequential. DirkvdM 08:03, 16 October 2005 (UTC)
A storage medium being defined as 'random access memory' has nothing to do with the time it takes to access a piece of data on the medium, but whether it may access a given piece of data on the medium in a 'random' fashion. Hard drives, for example, can certainly access sectors of data randomly, as can CDs, DVDs, and the like. This article on random access memory is myopic, dealing exclusively with forms of random access memory similar to the most familiar form -- like writing an article on tissue paper, but only talking about Kleenex. I'd fix it, but this discussion post just about satisfies my level of care and motivation.
Fishbert 06:23, 12 October 2007 (UTC)

History?

This is mainly about DRAM and SRAM (or "solid state" memory). What was used before (mechanical store, vacuum tubes, delay lines, magnetic drums, core memory...) ?

What about future developments (MRAM,FRAM, etc?) 80.133.130.82 12:46, 16 October 2007 (UTC)Christian

Likewise, for embedded RAM there is historical asynchronous, synchronous (registered inputs) and what is the industry standard name for registered outputs as well?

This article must be renamed

"Random access memory" is very generic term and absolutely not the same as main memory modules in a personal computer (which this article largely suggests). I have no problems with PC-centric articles like this, as long as they are properly named. Use, for instance, "Memory module", "DRAM-module", "RAM (personal computer)", anything but the current name, which simply is erroneous.

HenkeB 12:25, 26 July 2007 (UTC)

I'm afraid that's what it's called genraly! 88.109.32.61 (talk) 16:38, 25 November 2007 (UTC)

Article naming

How about moving Random Access Memory to Random access memory since the only reason it's capitalised is because it's mostly used as an acronym? Quoth 00:38, 11 Apr 2005 (UTC)

Oops, I should've been watching the article. In line with your suggestion, WKP policy is indeed to use the noncapitalized form of a term such as the present one---the acronym expansion of "RAM". I guess I should just go ahead and re-rename the article, but I'll wait a day or two to let it sink in. -Wernher 03:24, 19 Jun 2005 (UTC)
OK then; no protests at all, so re-rename "is go". --Wernher 19:07, 25 Jun 2005 (UTC)
Done. --Wernher 00:06, 26 Jun 2005 (UTC)
Sigh. Done, again, after yet another renaming. "Convention: Unless the term you wish to create a page for is a proper noun, do not capitalize second and subsequent words", as per WKP naming policy, linked to above. This also goes for acronyms standing for general phrases, i.e. not standing for proper nouns. Most university text books follow this re: "RAM".--Wernher 07:58, 10 March 2006 (UTC)

Terms made up of capitalised word tend to omit hyphens. Since the capitalisation has been removed here, there is no reason to omit the hyphen that ought to be between the two elements of the compound adjective "random-access". After all, this is memory of random access, not random memory of access. — Chameleon 03:41, 9 March 2008 (UTC)

MiB and KiB v.s. MB and KB

I note that this article uses “MB” to denote megabyte as in “8 MB of RAM”. Other articles on Wikipedia use “MiB” instead of “MB”. For interested authors, debate and a vote is ongoing on Talk:MOSNUM regarding a proposal that would deprecate the use of computer terms like “kibibyte” (symbol “KiB”), “mebibyte” (symbol “MiB”), and kibibit (symbol “Kib”). It would no longer be permissible to use terminology like a “a SODIMM card with a capacity of two gibibytes (2 GiB) first became available…” and instead, the terminology currently used by manufacturers of computer equipment and general-circulation computer magazines (“two gigabytes, or 2 GB”) would be used. Voting on the proposal is ongoing here. Greg L (my talk) 01:07, 28 March 2008 (UTC)

Some needed subjects: manufactuing grades, likelihood of errors, durability

Need a section on real-world RAM manufacturing, the concept of RAM grades and high-end and low-end manufacturers, and what this means in terms of possible errors and durability. —Preceding unsigned comment added by 76.199.67.233 (talk) 23:31, 21 April 2008 (UTC)

202.56.7.162 (talk) 05:22, 29 April 2008 (UTC)

Special Template Proposal?

I propose for the list of RAM type on the right hand side of the article we change it one of the 2 types of Template, so all RAM related article can be used, because a lot of non-popular RAM are not being included and it is not fair.

The first type of template (I don't know what Wikipedia call it), but this article use it Classical mechanics.

The second type of template is use by this article, Internet protocol suite and subsequently you add the linke (more) which either take you to a stub or it takes you the subcateogry section depending on if we want to expand it (if we have sufficient knowledge to expand it) or any other decision you/we wish to propose. --Ramu50 (talk) 19:07, 18 July 2008 (UTC)

See Also section

RAM is a study of computer data storage, and they are 2 types of storage RAM and ROM, this is also supported by CompTIA. Users should have right to navigate in the See Also section, since currently there isn't a template that explain that well. Also Computer Memory DOESN'T refer to RAM only, in Computing Science RAM is considered short term or temporary memory, while ROM is permanent memory and so forth and therefore you shouldn't be arguing about this, since these are factual information. --Ramu50 (talk) 22:17, 14 November 2008 (UTC)

No... "RAM" is not the study of computer data storage, nor is it "considered" to be a short hand term for "temporary" memory (I assume by "temporary" you mean volatile memory), although it may be the case in practice. "RAM" is an abbreviation for "random access memory", a type of computer memory defined as, "A memory designed so that the location of the data stored in it is independent of the content and any location in the memory may be directly assessed without having to work through from the beginning." My source? Pages 470-471, "The Penguin Dictionary of Electronics, Second Edition". ISBN 0-14-051187-3. Rilak (talk) 12:05, 16 November 2008 (UTC)

They quotation you cited shows no evidence that neither RAM nor ROM are considered memory. Well I should probably clarify what I said previously. They are 2 types of RAM (violatile / non-violatile memory) and NOR Flash. ROM, WORM...etc are mechanism of the RAM. --70.79.65.227 (talk) 03:35, 12 December 2008 (UTC)

So the definition of "RAM" in my source, which begins with, "A memory designed...", does not support the fact that RAM is memory? Rilak (talk) 04:23, 12 December 2008 (UTC)

Graffiti

Could someone please check this page. It appears someone thought it would be funny to put shout-outs to all their friends. I'd make the changes myself put thought it best for the original authors to do it. Thank you. Thewanderingmiller (talk) 14:26, 5 January 2009 (UTC)

File box?

Does the file box really need to be in this article? -charleca (talk) 16:58, 9 January 2009 (UTC)

I would say not. A box of index cards as pictured is really more akin to content addressable memory than plain RAM. Even then, it is more of a database example. I think we should drop it as a poor physical world metaphor than doesn't really behave in the same way. CrispMuncher (talk) 17:48, 9 January 2009 (UTC)

I've removed it. -charleca (talk) 15:17, 10 January 2009 (UTC)

And the original contributor has added it back. I've asked him to join us here for discussion. -charleca (talk) 12:18, 13 January 2009 (UTC)
Hey listen folks, whatever. I believe that a non-computer example will be the key to understanding this concept for some. Both of the articles content addressable memory, as well as this one state that they are forms of "computer" memory. That just is not the case in principle. In principle, the index card is also an example, and an excellent one at that. My guess is, that others with a bigger investment in the article will have their way with it. Please keep in mind that there is a world beyond computers for many of these computing concepts as you do so. Be well, Pontiff Greg Bard (talk) 20:59, 13 January 2009 (UTC)
I agree. "Ancient" forms of RAM...if they exist...should be included to get the point across to those who have no understanding of computers. The biggest issue we have with the file box is that it's more of a database than it is RAM. -charleca (talk) 21:33, 13 January 2009 (UTC)
Hmm, I think a better phsyical metaphor for RAM is a very large book with page numbers and a number on each page. To read a cell you turn to that page and read the number. To write a cell you turn to that page, cross out the old number, and write a new one. Dcoetzee 22:50, 13 January 2009 (UTC)
Actually a book would be serial not random access, especially with page numbers. That's why the index card example is apt. Good luck. Pontiff Greg Bard (talk) 23:07, 13 January 2009 (UTC)
I don't think so - if this were true, you wouldn't be able to examine page 300 without first examining all preceding pages. While it's true that most people can't turn directly to the page they'd like, they can get to it pretty quickly. I've never used index cards, but are they even numbered? What's the metaphor here? Dcoetzee 23:21, 13 January 2009 (UTC)
A book would be more like ROM. Dcoetzee is correct about the serial stuff. You have to start at the beginning to get to a later address - like driving down the street to get to your house (Or like a cassette tape). The index card drawer is used to store data that eventually may or may not be retrieved at a later date/time. The cards are indexed in alpha order (or whatever ordering is chosen) for easy access. Sounds like a database to me. -charleca (talk) 23:46, 13 January 2009 (UTC)
I think charleca meant to say that I was correct, based on the succeeding statement?! Furthermore, the common conception of a "book" includes the idea that it is read in order or it just doesn't make any sense. This is specifically NOT true of index cards. Sure you could open up to any page and read... but that's not how books are used, so therefore it's a bad analogy. That IS how index cards are used. Numbered? You can't seem to shake the computer stuff! Index cards don't have to be numbered to be considered random access memory. Another reason it is a more general, and therefore more useful example. Good luck folks. Pontiff Greg Bard (talk) 17:55, 15 January 2009 (UTC)
No, I meant Dcoetzee was correct...about "[If a book was serial] you wouldn't be able to examine page 300 without first examining all preceding pages." Your example of the index cards is still exactly the definition of a database - not RAM. -charleca (talk) 18:26, 15 January 2009 (UTC)
Like I said from the beginning... whatever. It is an example of a database, and a good example of random access memory. The two are not mutually exclusive are they? I'm just wondering what the resistance is? It is the type of example that really helps one understand the fundamental concept. It's not the most commonly thought of example, and this too makes it a good example. So I've come up with several reasons why it is a good example, and could probably come up with more.
A book is serial not random. Publishers have every capability of producing flash card format if necessary. Books have binding and sequential page numbers. That's serial not random access. Pretty much 99 times out of 100 if you pick up a book and randomly turn to a page ...it will not make sense without the preceding pages. That's the way it is meant to be. So this is just silly at this point. Be well, Pontiff Greg Bard (talk) 19:16, 15 January 2009 (UTC)
Is that really how you use books? When you look up "Zebra" in the dictionary you start at page one and read through the whole volume until you come to Zebra? Of course not. That is an extreme example of course, but consider a factual book you are referring to rather than reading. You look something up in the contents or the index and proceed directly to the relevant page. Of course some books, novels in particular, you start reading at the beginning and go through to the end but that is a usage pattern that does not effect the capability. Computer memory is also used in specific patterns - your computer would not be much good if it simply executed code from an arbitrary position in memory, or simply accessed any data in memory without regard to what that data was. Known positions are used, and many operations do involve linear sweeps through memory. Don't confuse the access pattern with the capability of access.
More troublesome for me, though is that the semantics of RAM and a card file are different. With a card file you don't use numbers or even say "I want the 41st card". Each card usually has a title and the cards are sorted on that title. In use you use a binary-style search to locate the card in question (i.e. "No, I want to go further on, no too far, so back a bit". That is keyed access, not random access. The non-random element is demonstrated by the fact that if you have the card file open at a particular card it is far easier to access the cards immediately before and after it that any arbitrary card in the file. By definition, that is not random access. CrispMuncher (talk) 22:57, 15 January 2009 (UTC)
The fact that index cards can filed and rearranged easily make them RAM. No one has to do anything like look at previous or succeeding cards AT ALL. Nobody cares if they have numbers on them or not. Nobody cares what was on the previous or succeeding card. Your characterization sure does seem to rely on your own narrowly defined notion of using index cards. Interestingly, the whole "book" objection was based on a wildly broad notion of a "book" (which cannot be rearranged at all.) So I'm thinking this is a cultural objection rather than an intellectual one. Perhaps an image of index cards not in a file box, but rather spread out on a surface would be more illuminative. However, it really should not matter as far as the degree to which it is an excellent example. In fact, are you ready for a shocker? Index cards are a better, more pure, more true-in-principle example of RAM than computer "RAM" (which has all kinds of things that it has to do). To the degree you do not like the example, that really only means you are equally confused about what RAM really is. Good luck. Be well, Pontiff Greg Bard (talk) 20:19, 17 January 2009 (UTC)

Oh dear, I am almost lost for words now. Have you actually read this article? Do you understand what is meant by random access? To quote the article:

The word random thus refers to the fact that any piece of data can be returned in a constant time, regardless of its physical location and whether or not it is related to the previous piece of data.

If you want a second source of evidence, a quick reference I just checked states:

random access The process of obtaining information from or placing information in storage, where the time required for such access is independent of the information most recently obtained from or placed in storage. —Data and Computer Communications: Terms, Definitions and Abbreviations, Gilbert Held, ISBN 0-471-92066-5

As I have already pointed out, the speed at which you can access a card depends on where you looked at the previous one. Even if we accept your proposed untypical arrangement where they are all laid flat on a table (which is not what the picture shows at any rate), they are going to take up a lot of space and you are going to have to physically reposition yourself to read a distant card. Not random access.

You assert that the fact that the data on cards may be quickly re-ordered is itself evidence that the cards are random access. Explain how this fits in with the definitions above, and find a good cite for it. I doubt you will be able to, because this is an operation that takes place on the record level (itself lending credence to the database argument) which is layered on top of rather than being part of the access model. CrispMuncher (talk) 21:14, 17 January 2009 (UTC)

Loss for words indeed. This is ridiculous. I'm pretty sure that the Church-Turing thesis provides for index cards without controversy. The "constant speed" issue is perfectly well applicable to a human using index cards as well. Every possible 'physical repositioning,' all 'taking up of space' is exactly represented one-to-one by the same thing in the computer. I really have to stand by my last statement. Be well, Pontiff Greg Bard (talk) 19:49, 18 January 2009 (UTC)
Do you want to explain how Church-Turing is at all relevant to this discussion, or are you throwing random CS terms in for good measure? Church-Turing addresses computability: it says nothing about performance. The constant access time measure is indeed the case for true RAMs (SRAMs and older DRAMs), and yes, that is the defining factor for RAM. You can't dress up cards as being random access. It is always going to take longer to acess a card ten feet away that it is one right in front of me. CrispMuncher (talk) 21:13, 18 January 2009 (UTC)
The Church-Turing thesis states (in one formulation) that what is human computable is machine computable. Any step taken by one corresponds one-to-one to a step taken by the other. It is not a far leap to the index card analogy. Pontiff Greg Bard (talk) 05:57, 19 January 2009 (UTC)
If it is not a far leap then why don't you make it because I still can't see your point? You seem to have attached a much broader definition of computability than is used in that area, indeed your revised working definition appears to fundamentally break the body of work you reference. Computability is distinct to storage: lambda calculus does not address storage at all and while a Turing machine does, it does not possess random access memory. You have brought in what appears to be completely irrelevant area and have yet to show how it links in. I'm still awaiting that cite I asked for earlier by the way.
In the mean time until you clarify your position I'm once again removing that image since at the moment the balance of opinion is against you. The most frequently given real world metaphor for RAM is a pigeonhole message box rather than a card file since its behaviour more closely models that of RAM. However, even for that the comparison is not perfect since the an individual box may be empty, or conversely, have more that one thing in it. CrispMuncher (talk) 20:24, 19 January 2009 (UTC)

I missed most of this discussion, but it has spilled over to the Data storage device article. I didn't see a problem with calling the example there "random access" with the small edit to the caption of calling it "manual" access. I understand that this is not the conventional way we view random access. But conventional thinking rarely advances technology. I also understand why it may be a problem on this page because it's mainly about electronic access. But the Data storage device page is of a broader topic. I always thought that "random access" just meant non-linear access. What more does it mean without writing our own dictionary here? And why is the information in a file box not randomly accessed? For now I'm going to put the image back and modify the caption again. Feel free to advise on this talk page or that talk page on the new caption. Oicumayberight (talk) 21:06, 19 January 2009 (UTC)

The key difficulty is that "random access" has a precise definition. It means that any record can be accessed as easily and as quickly as any other. This isn't the case with a card file since if it is open an a particular entry the neighbouring cards (before and after) can be accessed faster than a more distant card even in the same box or drawer. The first and last cards in the draw are always comparatively easy to find regardless of the current location. It is true that you don't need to read or even look at every card to find the desired one, but you still have to navigate towards it. Ultimately the mechanism is similar to that for a hard disk: you can rapidly get to any entry in the storage "device" but the time taken to access a record is not constant, but related to how "distant" (which may be defined in many factors, not just physical distance) the desired entry is from the current position within the storage device. That is often termed "direct access" to differentiate it from tape drive-style sequential access but still not confuse it with random access.
The card file box is a reasonable metaphor of RAM, although better ones are available. However, the captions as presented do not describe it as a metaphor but as a real example of the specific concept: this is stretching too far and presenting something as identical when in fact it is merely similar. There is also another problem with the card file example in that additional structure is frequently used with card files - there is a "key" of some sort, such as a name, and the cards are filed based on that key enabling records to be quickly found as for other paper filing systems. This is keyed access, which is itself a form of direct access but more flexible in its application on top of specific technologies. However, asserting this example as random access memory also risks confusing the reader with another layer of abstraction that this metaphor uses, but RAM doesn't. Keyed access is more of a database concept which makes it strikingly out of place here. CrispMuncher (talk) 21:36, 19 January 2009 (UTC)
Understood. Oicumayberight (talk) 21:44, 19 January 2009 (UTC)

Can you explain to me how do you determine the minimum amount of ram required to run a program thank you —Preceding unsigned comment added by 71.204.124.40 (talk) 08:14, 8 April 2009 (UTC)

Comparison of typical consumer chips

I also thought this article was hard to understand. A couple of years ago when I last looked up this topic there was a nice comparison/identification table looking at what most people consider to be RAM - that chip which you stick in a PC. Now the section is larger with all sorts of different types but no good overview. Instead this article is full of out-of-context excessive details - it is spotty.

The section on packaging has probably the most useful information for the layperson. But it is at the bottom. (as it should be, given that this is supposed to: first, describe what RAM is in generally - second, give an overview and map to all the other articles about specific types of RAM)

I suggest we have a seperate article about packaging and typical lay user choices that need to be made, linked very prominently, near the top or in the opening paragraph. This would include basic timeline linking to history elsewhere. Size of chip/compatability/graphics and measurments to help identify. Basic properties and comparison linking to actual articles on each type. Maybe also some economic analysis, such as what types actually get used.

Also, technical names and names commonly used in business to sell this stuff differ. This information needs to be somewhere. When a sales flyer says SDRAM it is shorthand for a certain type.

Right now the expertise and details of wikipedian's knowledge are detracting rather than helping this article section. Organisation of the ideas better would cure that.

Unfortunately I am naive in this topic so I fear making such dramatic changes I would do it wrong. Hopefully someone with the knowhow could try it.

Thank you to all wikipedians for being so awesome! MY apologies for suggesting but not doing. --Rusl 18:36, 10 July 2007 (UTC)

I am also somewhat confused about "RAM," "Cache," and "main memory," how they are similar or different in usage. —Preceding unsigned comment added by Skysong263 (talkcontribs) 22:14, 23 November 2009 (UTC)

Linux swapping

The following paragraph was removed from the swapping section by a new user (his/her only edit). Technically it's not cited, but it looks like it could probably be put back in the article. Llakais 20:10, 24 November 2009 (UTC)

On some operating systems (such as Linux) it is possible to turn swapping off such that no memory is written to the hard disk ("swapoff -a" as superuser on startup). This can reduce latency as well as hard disk wear, but if one does not have enough RAM then the OS will freeze and perhaps kernel panic. [citation needed]

what is a role of Ram?

what is a role of Ram? —Preceding unsigned comment added by 80.255.50.2 (talk) 17:24, 18 April 2010 (UTC)

Doublepost

The history and overview paragraphs are the same. I think the overview paragraph should be removed. does any one else agree?? —Preceding unsigned comment added by 74.15.52.181 (talk) 22:19, 8 June 2010 (UTC)

yes I think the overview should be deleted it is way to soon in the article for an overview and like U said it is just a double post a summery at the end would be betterurName (talk) 03:47, 15 June 2010 (UTC)


Shadow RAM section

I don't think this belongs into general article about RAM. Shadow RAM is a BIOS feature which just happens to use RAM because it is faster. It could be "Shadow (insert faster than ROM chip)"...

Shadow RAM is a general feature, not limited to BIOS use, the standing article on shadow ram was merged into this article and the keyword now redirects here. If discussions of swapping, virtual memory, and other special-use regions of memory are here, then a ROM shadow is appropriate.

-- moved here from article: dram needs one capacitor and one transistor for storing one bit. It refresh within mili seconds for storing data -- s barathi —Preceding unsigned comment added by 117.206.112.52 (talk) 13:56, 21 August 2010 (UTC)

Kind of a short article, isn't it?

Take a look at the CPU article for comparison. Tons of more info listed on it.

Perhaps we should put up the template for expansion? —Preceding unsigned comment added by Klosterdev (talkcontribs)

Sure. I don't know what it is; go ahead and add it. --SheeEttin 12:57, 3 June 2006 (UTC)
To be fair, there is far less to be said about solid state RAM than CPUs. -- uberpenguin @ 2006-06-03 18:29Z

Somebody really said there is less to be said about RAM than CPUs?!?! Well, once we get the first couple of hundred thousand words about both then such a comment wouldn't be risible. This article not only blurs th clear distinction between ROM and RAM, it conflates random access with RAM. I'm disappointed69.40.254.72 (talk) 14:05, 3 December 2010 (UTC)

Random access

the term random access memory means the cpu can access any bit anywhere in memory in non sequential fashion early computer did not have RAM or Disk drives but instead used ROM and Magnetic tape's data on the magnetic tape's was stored sequentially along the entire tape bit by bit in order to access any data on the tape it would have to be played back from begining to end until the desired data was found and retrieved. Today we have hard drives to store data you can think of RAM as go between your hard drive and your actual CPU, OR as RAM being part of the CPU "cache", RAM is like a pencil and paper for your computer to write out it's equations before it does the actual work of solving a problem or writing data.urName (talk) 15:44, 15 December 2010 (UTC)

Talk pages are for discussion of improvements to the article. What, exactly, are you recommending should be changed in the article? --Wtshymanski (talk) 15:51, 15 December 2010 (UTC)
I was just trying to answer other peoples questions about the article i have no wish to edit the article sorry if i caused trouble, but is it ok to do that?urName (talk) 18:43, 15 December 2010 (UTC)
He was trying to respond to another section in talk, Wtsh, but hasn't quite mastered how to edit a section. Which section were you trying to respond to, urName?
Oh, were you trying to respond to 'what is a role of Ram?'? Either you or one of us can move your post if that's ok. -- Fyrefly (talk) 15:34, 16 December 2010 (UTC)

Core 2 Duo mention

In the "Memory Wall" section, it mentions the Core 2 Duo processors, referring to them as "new", and suggesting that they may represent a turnaround in the slowdown of progress in CPU speed. Not only is this a wild and entirely unwarranted extrapolation based on a suspicious statement that isn't even sourced, it is also five years out of date. I can't really think of a way to fix it other than just deleting it, which I don't want to do because I feel like there might be some meaning to it that I missed. Someone should fix that. 71.192.28.49 (talk) 03:03, 26 February 2011 (UTC)

Marked with "citation needed" and made past tense.Jasper Deng (talk) 03:20, 26 February 2011 (UTC)

Read only vs random access

ROM is not RAM in the article under the Types of RAM section it says "RAM of the read only type, ROM, instead uses a metal mask..." I think its trying to say ROM a type of read only memery uses a metal mask... I also think it doesnt belong in the Types of RAM section it would work better under a new section "Other types of memery" because ROM is not Random access and the tittle of the section in Types of RAM so i recomend just changing the tittle of this section to Types of memery and fix the wording "RAM of the read only type, ROM instead..." urName (talk) 21:43, 8 January 2011 (UTC)

I took care of this - did a complete rewrite of the section in May. — KieferSkunk (talk) — 14:49, 24 May 2011 (UTC)

Current RAM vs. ROM issues

I see this has been discussed before, but the article still has issues with the distinction between RAM and ROM, and seems to be treating these generic terms as the only possible ways to refer to storage. I think there are several problems that need to be resolved in this article:

  • First off, RAM is not ROM, and ROM is not RAM - the two terms are mutually exclusive, and overlaps between them are explained through the applications of the various devices. It is true to say that ROM *can* be read in random order, but it is generally very slow for this purpose, so referring to "Read-only RAM" is incorrect when referring to ROM, and is misleading if you're talking about an advanced application of RAM.
  • Second, data storage mechanisms such as hard drives, flash memory, etc., are not RAM. They share some characteristics with RAM, but in the majority of cases have more to do with EPROM, EAROM, etc.
  • and Third: The line blurs a bit with flash memory, but forms of semi-permanent or permanent storage, such as hard disks, magnetic tapes, DVD-RAM, etc., are really neither RAM nor ROM in the strictest sense, since they are not solid-state devices. Data storage is really in a category all its own, and only certain characteristics of both ROM and RAM apply to it.

As of right now, the opening paragraph is likely to be very confusing to the average reader. — KieferSkunk (talk) — 15:06, 24 May 2011 (UTC)

Should memory wall be mentioned so prominently?

Related to the previous question, so this seems to be where to put it, even though both the previous question and this one feel like rather random insertions... The topics of memory bandwidth, access, and mismatches are worth discussion (though I think it would still be hard to provide a clear or simple answer to the previous question), but the notion of "memory wall" seems rather too nebulous to deserve inclusion in the article. The term "memory wall" is not even mentioned in the cited reference from Intel... It seems to be an idea that was introduced in the mid-90s, but it never caught on. (Or perhaps it was overwhelmed by the non-computer usage?) Shanen (talk) 08:09, 22 July 2010 (UTC)

The cited reference does mention the von Neumann bottleneck, which currently redirects to the von Neumann architecture article.
I suggest we create an article discussing the von Neumann bottleneck and move all the text from the "memory wall" section of the random-access memory article to that article, leaving behind a one-sentence WP:SUMMARY.
Should the new article discussing this bottleneck be titled "Von Neumann bottleneck",
or would some other title ("memory bottleneck", etc.) be better?
--DavidCary (talk) 12:00, 3 August 2011 (UTC)

Williams Tubes and mercury tanks

The article is incorrect. The article says the magnetic cores were the first kind of random access memory. I do believe that Williams tubes (which are cathode ray tubes and not what people usually think of as vacuum tubes) and mercury tanks are also examples of random access memory that predate the development of magnetic core memory by several years. —Preceding unsigned comment added by Mendax666 (talkcontribs) 16:38, 4 July 2008 (UTC)

The first true random access memory was indeed the Williams tube used on the Manchester Small-Scale Experimental Machine of 1948. — Preceding unsigned comment added by 80.4.57.101 (talk) 17:41, 19 October 2011 (UTC)

Mixing RamTypes

I have a 256MB PC2700 ram chip that came with my HP Pavillion A1000y. I also have a 512MB PC2100 chip I took out of a Dell Optiplex GX2600. Will mixing ram affect my computer's performance any? And I think there should a section be made about mixing ram. —Preceding unsigned comment added by 75.105.128.56 (talk) 03:56, 4 October 2008 (UTC)

This is really a question for a technical forum. And AFAIK, there's not really enough notability in this particular topic for there to be a whole section on it. To answer your question, tho, you really can't mix RAM like that - if the machine will work at all, it will likely be very unstable. In some cases, it might work but would work at either the slower RAM's speed, or at some common denominator between the two RAM chips. Either way, it's a bad idea. — KieferSkunk (talk) — 01:48, 20 October 2011 (UTC)

Request: Block RAM

I would like to see some info about RAM used on FPGAs like block RAM.188.97.12.36 (talk) 09:46, 28 February 2012 (UTC)

Feedback on this article's accessibility to non-technical readers

This article has been used as an example of Wikipedia articles that could use a less technical intro/overview for a non-technical audience. Perhaps some work on the lead section is in order? -Pete (talk) 20:53, 22 July 2012 (UTC)

Suggestion: Random-access memory to Random access memory

Random access memory is abbreviated RAM not R-AM, it seems irregular in its current form. Afree10 (talk) 11:32, 26 June 2013 (UTC)

Is Pentium 4 a good counterexample to the memory wall problem?

The memory wall section contains p4 as a counterexample but this is mistaken imo: p4 was very much a discontinuation of the p6 line (ppro, p2, p3, pm, c2d, i7) with lower ipc in order to achieve higher clock rates, like the amd fx now does, so it wouldn't be useful for examining the memory wall problem. Perhaps we'd better compare chips with more similar architectures? Sofia Koutsouveli (talk) 15:50, 23 March 2014 (UTC)

need info on RAM

i have a situation here , i was typing a document on my computer and the power to the computer was interrupted momentarily. when the computer was restarted the document was no longer in memory. can u explained to me why the document was no longer in the memory. — Preceding unsigned comment added by 72.252.133.113 (talk) 19:44, 26 September 2013 (UTC)

Section on installing RAM

This article should have a section about installing RAM and where/how the RAM fits into a standard desktop or laptop. 74.46.203.31 (talk) 20:17, 24 October 2011 (UTC)

No, it should not. Wikipedia is not a substitute for your owner's manual. There are a million trivial differences in the procedures and none of them are of significance to an encyclopedia. Mentioning that users do install their own RAM, that different procedures are required for different computers, a citation of how much after-market RAM is sold for field installation - that would be good to have in an encyclopedia article. But a list of which screws to turn and which sticks to buy is not. --Wtshymanski (talk) 04:21, 27 October 2011 (UTC)
Would it be useful to have videos of photos of installation of various technologies of primary memory like core memory, SIMM, DIMM etc.? Sofia Koutsouveli (talk) 15:57, 23 March 2014 (UTC)
What would a video show? We're not supposed to be a how-to guide, and unless we want to highlight the difference between a gang of IBM technicians in 1964 hooking up a cabinet of RAM to a mainframe vs. someone popping a 16 gig SD card into a camera, I'm not clear on the encyclopdiac value. I would say, no, no "installation" (verb) videos, and we have a few pictures of installations (noun) of core and semiconductor memory already in the article. --Wtshymanski (talk) 20:01, 24 March 2014 (UTC)

Electrical Propulsion

What can be used to time out when a burst of electricity should be sent? — Preceding unsigned comment added by 66.213.10.5 (talk) 14:56, 30 August 2014 (UTC)

Edits by 203.173.178.51

User 203.173.178.51 has been repeatedly making the same edits. Is there any benefit coming from them? I want to reach a consensus instead of playing the revert game. --bojo1498 talk 14:26, 17 December 2016 (UTC)

Just plain RAM is general, for all digital computers; not cache RAM or "RAM disk;" they are different things!

Okay, we have at least two editors—one in particular—who are edit-warring, incorrectly replacing wording that falsely implies that "RAM is used in a computer to help it increase speed," who act as if an IP-based editor like me "couldn't possibly be correct." While it is sometimes possible to increase the speed of a computer by widening a bottleneck by adding RAM, this is not the main role of RAM. A computer needs some RAM at all just to be able to run. Indeed, a true, Turing-complete computer can't even exist without RAM. The thing these two edit-warriors may be getting general RAM confused with is a bit of RAM that's set apart as a "RAM disk," which software is preloaded into at bootup, is used more by some old computers of the 1990s. A modern PC or Mac, however, can preload software at bootup, but needs no "RAM disk" setup to do so. However, it still must have RAM to even run. So can we please agree not to keep warring this inaccurate opinion about why RAM exists and is installed into computers? 2600:100E:B141:AE59:1B4D:9EA7:5CC5:82E1 (talk) 16:52, 4 October 2017 (UTC)

If RAM were installed in a system in order to increase speed, it would not be necessary for a computer to work. So, in the case a computer does not have RAM, how will the CPU fetch a single instruction? Storing frequently used instructions in order to increase speed is the role of cache, not RAM. Hayazin (talk) 19:10, 4 October 2017 (UTC)
Well, Hayazin, cache is RAM too, but it's not the main RAM. So we have cache RAM (L1, L2, etc.) and then the main RAM. But your reply here is still accurate enough to help us form the consensus to go back and correct the article accordingly. So thank you! And thank you too, Crystallizedcarbon, for accepting my sensibly necessary corrections of the nonsense implication that someone was trying to enforce before. 2600:100E:B141:AE59:1B4D:9EA7:5CC5:82E1 (talk) 04:38, 5 October 2017 (UTC)

Semi-protected edit request on 8 July 2019

Apologies for any incorrect terminology, this is my first ever edit/edit request and I literally only made this account to fix this small error.

Remove the second paragraph of this article ("A random-access memory device ... such as media rotation speeds and arm movement.") since it is mostly duplicated from the first paragraph. SchnastMaster (talk) 15:05, 8 July 2019 (UTC)

 Done, thanks for pointing it out! ‑‑ElHef (Meep?) 15:15, 8 July 2019 (UTC)

Rapid-access memory

Some time ago i've changed the current

Random-access memory (RAM /ræm/) is a form of computer data storage that stores data and machine code currently being used. A random-access memory device allows data items to be read or written in almost the same amount of time irrespective of the physical location of data inside the memory. In contrast, with other direct-access data storage media such as hard disks, CD-RWs, DVD-RWs and the older magnetic tapes and drum memory, the time required to read and write data items varies significantly depending on their physical locations on the recording medium, due to mechanical limitations such as media rotation speeds and arm movement.

to

Random-access memory (RAM /ræm/) is the most common type of memory used for a Rapid-Access Memory which is a form of computer data storage that stores data and machine code currently being used.

A Random-Access Memory device allows data items to be read or written in almost the same amount of time irrespective of the physical location of data inside the memory. In contrast, with other direct-access data storage media such as hard disks, CD-RWs, DVD-RWs and the older magnetic tapes and drum memory, the time required to read and write data items varies significantly depending on their physical locations on the recording medium, due to mechanical limitations such as media rotation speeds and arm movement.

with this comment

(Rapid-access memory is a part of computing system, Random-Access Memory is a type of memory, one of many examples: https://www.semanticscholar.org/paper/An-experimental-rapid-access-memory-using-diodes-Holt/566a45ed0fefdf088e94c9c31ddd311a35602ada)

thats not only an obviously logical and self-explaining correction( that doesn't require a confirmation), but i've also linked a related patent as an example(/"source").

But at 19:24, 4 July 2019‎, Maestro2016 have reverted this to a wrong version with this comment "" "Rapid-access memory" isn't sourced or mentioned anywhere else in the article." "", the wiki doesn't have a dedicated Rapid-access memory article and i'm not going to create it, but that doesn't change the fact of that the selected text has the wrong statement, so i'm making this topic in a sake of fixing the issue.

Ilias48rus (talk) 18:29, 9 July 2019 (UTC)

(Ofcourse the Rapid-access memory term have its description right after it because there is no the linked page) Ilias48rus (talk) 18:40, 9 July 2019 (UTC)
i've just remembered that Rapid-access memory page actually even exist on Russian wikipedia -- https://ru.wikipedia.org/wiki/Оперативная_память . Ilias48rus (talk) 09:34, 10 July 2019 (UTC)->
that should be checked, but its possible that the "Random-access memory" was never intended to be shortened to "RAM" since any practically used/existing Random-access memory systems are 1 of it's types (alike the DRAM are the most common one used for a PC's Rapid-Access Memory). Ilias48rus (talk) 10:05, 10 July 2019 (UTC)
Nowhere does the link you cited claim that "RAM" stands for "rapid access memory", or that it's an alternative name for "random-access memory". That's a big misprepresentation of the source. Almost every other source in the article is in agreement that "RAM" only stands for "random-access memory". Maestro2016 (talk) 11:58, 10 July 2019 (UTC)
Also, this is English Wikipedia, not Russian Wikipedia. Even if "rapid-access memory" is used in Russia, you'll need reliable English-language sources clearly stating that "rapid-access memory" is an alternative name for "random-access memory" or "RAM". Maestro2016 (talk) 12:22, 10 July 2019 (UTC)
1. "Rapid-Access Memory" is not an "alternative name" for a "random-access memory", its a 2 different things, and the source page i provided means that the "computer data storage that stores data and machine code currently being used" are named a "Rapid-Access Memory", 2. i nowhere stated that the "RAM" term unfolds to the "Rapid-Access Memory", because i do not have a source to confirm this, i've just posted a possibility of this in the talk page. According to this, your stated reasons for undoing the change are false. Ilias48rus (talk) 15:24, 10 July 2019 (UTC)
The other sources also may state: 3. that the "Random-access memory" mean the Rapid-access memory too -- this is because all the Rapid-access memory units are basically a Random-access, or 4. that the "Random-access memory" mean the same as a "Rapid-access memory" -- this is because its a common misconception; Ilias48rus (talk) 15:32, 10 July 2019 (UTC)
Here is the 2nd source -- https://www.gktoday.in/gk/rapid-access-memory-ram/, a 3rd -- "rapid+access+memory"&source=bl&ots=ND1g_UNFsC&sig=ACfU3U1k-7fe3_oS-16Vr9OCGrxT2L__7A&hl=en&sa=X&ved=2ahUKEwj4wLDg16rjAhVOGpoKHWvIDnwQ6AEwDnoECA4QAQ#v=onepage&q="rapid%20access%20memory"&f=false, 4th -- "indexing for rapid random access memory systems" (http://www.bitsavers.org/pdf/computersAndAutomation/195612.pdf): "24. Recent Developments in Very-High-Speed Magnetic Storage Techniques, by W. W. Lawrence, Jr., IBM Research Center, Poughkeepsie, N. Y.: Developments of new magnetic elements have shown that rapid access memory systems with complete operating cycles of a fraction of a microsecond are feasible.";, with that i've stated before its not enough for you ? Ilias48rus (talk) 15:52, 10 July 2019 (UTC)
(do not forget that this is not about sources, its a basic logic and the language, you do not think with the own head or think that for example an HDD can't be used instead of the RAM chip electrically or programmably?) Ilias48rus (talk) 16:06, 10 July 2019 (UTC)
None of those sources give a clear definition of what "rapid access memory" even means. Do you have a reliable source that actually has a clear definition of what "rapid access memory" means? Maestro2016 (talk) 16:57, 10 July 2019 (UTC)
The 2nd source -- GKtoday says a "Memory" and a "Physical Memory", i haven't noticed this, but the 3rd -- "International dictionary of abbreviations and acronyms of electronics" says that the Rapid-Access Memory is an existing term. The 2 others use it with it's meaning, its a self-explanatory, more a word-set than a "term", there is no possible source that could give what you want except of a dictionary. I'll add the Windows's "System Memory" name of the "Rapid-Access Memory" to make the sentence more reliable. Ilias48rus (talk) 17:12, 10 July 2019 (UTC)
Okay, so none of those sources explain what "rapid access memory" actually means. If you want to add it to the article, you'll need to reference a reliable source actually explaining what the term means. Simply saying it's "self-explanatory" is not good enough, but that's just WP:Original research. As per WP:VERIFIABILITY, everything on Wikipedia needs to be verifiable with reliable sources. Maestro2016 (talk) 17:20, 10 July 2019 (UTC)
Right as i said, the 1st and 4th examples gives the meaning and the 3rd formalises the term. However this doesn't matter because as i've also said its more a word-set and not a term (its a combination of English words that form a meaning, i do not state it to be the formalized term). Ilias48rus (talk) 17:30, 10 July 2019 (UTC)
Do you have any WP:Reliable sources clearly stating that "random-access memory" is a form of "rapid-access memory"? The first source makes no such connection. The second source is not a reliable source. The third source also draws no connection between "random-access memory" and "rapid-access memory". And the fourth source also does not claim that "random-access memory" is a form of "rapid-access memory". Maestro2016 (talk) 18:02, 10 July 2019 (UTC)
RAM is not a form of the rapid-storage memory, the RAM is a method/system of storing the data, the rapid-storage memory or a System Memory is a programmatically selected data storage unit/area (regardless of it's structure/system). Why GKToday aren't considered to be reliable?, .. now i planned to list dozen of sources to confirm the first sentence, but i've noticed a Computer Memory page and with some other places including the Computer_hardware#Motherboard this started to make sence: the result are in the 3rd edit, and the "Primary Storage" are a term that covers the subjected Rapid-Access Memory meaning, that also returns the word-set from the status of ambiguation. Ilias48rus (talk) 19:35, 10 July 2019 (UTC)

Ilias, "rapid-access memory" is not a term we conventionally use in English (a few authors may have used it descriptively, but it's not a thing). If I'm wrong, show us the English-language sources about this. Please stop edit warring and let's work this out in talk. Dicklyon (talk) 20:55, 10 July 2019 (UTC)

See usage stats from books. Dicklyon (talk) 21:38, 10 July 2019 (UTC)

Pointless revert

1st article to

Random-access memory (RAM /ræm/) is a form of computer data storage, or a ready to use Circuit board (usually DIMM) with a mounted RAM chips. A random-access memory device allows data items to be read or written in almost the same amount of time irrespective of the physical location of data inside the memory. In contrast, with other direct-access data storage media such as hard disks, CD-RWs, DVD-RWs and the older magnetic tapes and drum memory, the time required to read and write data items varies significantly depending on their physical locations on the recording medium, due to mechanical limitations such as media rotation speeds and arm movement. RAM are usually used as a computer's primary storage.

Because of

"(This is important to understand that: 1. a scheme/ technology( alike a computer data storage) and a realized/working system is a different things, and 2. duplicating things alike saying that RAM store a currently used machine code and a Primary Storage store a currently used machine code, without relating 1st as a type of the 2nd, is an ambiguation thing and a subject of confusion.)"

Anyone mind ??? Ilias48rus (talk) 01
33, 11 July 2019 (UTC)
Ilias48rus, is you want to discuss an edit or a revert, please provide a diff link, which you can copy from the page history. It is difficult to interpret your oddly-formatted talk. Dicklyon (talk) 21:48, 10 July 2019 (UTC)
If you're referring to my big revert to before today's edit war, that was not based on any review or decisions on content, just on the observation that there's an edit war and the more stable version of yesterday is a better base to discuss from. And the observation that you're adding a term unknown to us in English as I mention above. Dicklyon (talk) 21:51, 10 July 2019 (UTC)
The new term's case was closed with the my last message in the topic above, the 3rd/last edit was out of the issue, the diff are of "19:54, 10 July 2019"‎. I didn't refer to the your revert, this topic is a consequence of it (you by self have marked the change as requiring a discussion). Ilias48rus (talk) 22:11, 10 July 2019 (UTC)
Re this edit, I mind, which is why I reverted it. It complicates the lead sentence with irrelevant details and complicated syntax, when the first sentence should be a simple and clear introduction to the topic. - MrOllie (talk) 22:18, 10 July 2019 (UTC)
its the one of "19:43, 10 July 2019‎", i've updated it after the your revert, to the one of "19:54, 10 July 2019‎" (link) Ilias48rus (talk) 22:22, 10 July 2019 (UTC)
Have "updated" to solve the controversy, to be clear. Ilias48rus (talk) 22:37, 10 July 2019 (UTC)
Those changes do not address my concern, which is the adding of unnecessary (and arguably incorrect) details about specific hardware form factors. - MrOllie (talk) 23:49, 10 July 2019 (UTC)
That is a different point and are the subject of the discussion with Maestro2016, that go below. Ilias48rus (talk) 23:54, 10 July 2019 (UTC)
To add, Ilias48rus seems to be confusing the actual RAM memory chips with the DIMM circuit boards. The actual RAM memory is in the IC chips, not the DIMM boards. RAM is usually sold to manufacturers as IC chips, not circuit boards. And then those manufacturers either use those RAM chips in the processors or circuit boards of their products (e.g. graphics cards, processor cache, game consoles, embedded systems, etc.) or sell a stack of RAM chips in a DIMM board. In other words, the RAM is referring to the IC chips, not the circuit boards which use the RAM chips. The change that Ilias48rus wants to make to the lede sentence is pointless and unnecessary. Maestro2016 (talk) 22:41, 10 July 2019 (UTC)
The sentence you referring to -- "or a ready to use Circuit board (usually DIMM) with a mounted RAM chips", mean that the "RAM" are used to name an entity that consist of the DIMM board and the RAM chips, i do not see any language/syntax mistake here ,so it could be misunderstood. When you come to a computer shop and say "what RAM do you have?" you get shown the DIMM and other boards, that the change is about, because the RAM "computer data storage" technology are not a thing "that stores data and machine code currently being used" as the current version state, the RAM hardware do. Ilias48rus (talk) 22:49, 10 July 2019 (UTC)
You missed the point. The RAM used in graphics cards, CPU processors, mobile phones, game consoles, embedded systems, etc. have nothing to do with DIMM circuit boards. The actual RAM is the memory cells. Millions or billions of those RAM cells are then integrated together to form an integrated circuit (IC) memory chip. And then those memory chips could be embedded into various systems or circuit boards. Referring to RAM as some kind of circuit board or DIMM is highly misleading, and is a misunderstanding of what RAM actually is. Maestro2016 (talk) 23:22, 10 July 2019 (UTC)
Definition of "RAM" according to Oxford: "computer memory in which data can be changed or removed and can be looked at in any order (the abbreviation for‘random-access memory’)". This is what "RAM" actually means, not some kind of circuit board. Maestro2016 (talk) 23:22, 10 July 2019 (UTC)
No, i saw this and was going to add some changes to the last sentence -- "RAM are usually used as a Primary Storage" because of this point you've wrote, but its you are missing this: the piece of PC hardware that intended to be operated as a Primary Memory have and must have its name, if the "RAM" term mean only a technology, it doesn't mean the hardware. Attention: maybe its the only ICs name?, then the dedicated piece of hardware is a -- RAMs that are distributed being installed in the board, in this case the proposed edit are:

{ Random-access memory (RAM /ræm/) is a form of computer data storage, or a ready to use Integrated circuits. A random-access memory device allows data items to be read or written in almost the same amount of time irrespective of the physical location of data inside the memory. In contrast, with other direct-access data storage media such as hard disks, CD-RWs, DVD-RWs and the older magnetic tapes and drum memory, the time required to read and write data items varies significantly depending on their physical locations on the recording medium, due to mechanical limitations such as media rotation speeds and arm movement. The RAM chips are widely used as a computer's primary storage usually being distributed installed in a DIMM boards. }

more issues? Ilias48rus (talk) 23:51, 10 July 2019 (UTC)
While that's an improvement, it's still problematic. RAM could be an integrated circuit, but it could also be simply a memory cell, or a transistor, or even magnetic-core memory. The oldest forms of random-access memory were tubes, then magnetic-core memory, and then discrete transistor memory cells, before IC memory chips came along. RAM is more of a general method of accessing memory (random access), rather than simply a piece of hardware (whether it's an IC chip, circuit board, or something else). In other words, the opening lead sentence is fine as it is. It's not necessary to change it. Maestro2016 (talk) 00:23, 11 July 2019 (UTC)
As MrOllie mentioned above, these are simply form factors. It's not necessary to mention the hardware form factors (e.g. memory cells, integrated circuit, circuit board, magnetic core memory, etc.) in the opening lead sentence. These are unnecessary trivial details, which could be mentioned further down below, but not in the lead sentence. The opening lead sentence should be simple, clear and concise. What you're suggesting is redundant information that isn't necessary in the lead sentence. See MOS:LEADSENTENCE for more information on how a lead sentence should be written. Maestro2016 (talk) 00:28, 11 July 2019 (UTC)
According to a Cambridge English Dictionary, the "Technology" may mean an entity developed by a technology(in its normal meaning), that makes the type of a computer data storage able to mean the hardware entity, that you have tried to say. You just needed to focus on why the term can mean the both entity types and not just repeat again and again that it do so. Ilias48rus (talk) 00:52, 11 July 2019 (UTC)
According to the same Cambridge English Dictionary, the definition of RAM is "random access memory: a type of computer memory that can be searched in any order and changed as necessary". It does not define RAM as a specific hardware entity. RAM can take a number of different hardware form factors (e.g. transistor cells, IC chips, PCB boards, magnetic-core memory, tubes, etc.). It's not necessary to mention any of those hardware form factors in the lead sentence, which should just be a simple, concise definition of what RAM means, at its most basic. Maestro2016 (talk) 01:04, 11 July 2019 (UTC)
The my point was based not on that the RAM mean a certain realized entity but on that the "technology" can't mean a realized entity, because of this the RAM had to have a 2nd meaning of the realized entity of a certain form/type or other definition that would cover use of the term for such entities. Ilias48rus (talk) 01:31, 11 July 2019 (UTC)
The physical entity you're referring to is called a "RAM chip". Which is one of several hardware form factors that RAM can take. Again, that's not something which should be mentioned in the lead sentence. That's something which could be mentioned further down, but certainly not in the lead sentence. Maestro2016 (talk) 01:52, 11 July 2019 (UTC)
Ilias48rus, I do not understand the point you are trying to make (your English is a bit of difficult puzzle for me to interpret), but I agree that the lead has no reason to mention embodiments of RAM such as ICs and DIMMs, even those are probably the currently most common embodiments. You also find RAM subsystems inside other kinds of chips such as CPUs, SOCs, FPGAs, etc., as well as in various more obscure places, not to mention vintage places like core memory systems. Dicklyon (talk) 05:24, 11 July 2019 (UTC)
You both seem probably missing that with the my post that starts with the "According to a .." i've confirmed/agreed that Maestro2016 was right about the result, however the subjected 1st sentence names RAM a technology, so if the "technology" couldn't mean an entity structured to utilise the technology, the sentence would be wrong, regardless of where the mistake is. Ilias48rus (talk) 10:27, 11 July 2019 (UTC)
Oh, i almost forgot about the other points in the 3rd edit. The 4th version are about separating the RAM's and a Primary Storage's meanings. Ilias48rus (talk) 12:45, 11 July 2019 (UTC)
I've changed the lead sentence to match the Cambridge and Oxford definitions of "RAM". Maestro2016 (talk) 20:53, 11 July 2019 (UTC)

Edit request

On the 1st line of the Types section "The two widely" should be "The two most widely". Tomasantunes (talk) 18:13, 16 April 2020 (UTC)

Fix intra link

In section Random-access memory#Memory wall, instead of linking to Resistance-capacitance (which is very long and doesn't explain the relevance of this delay), link to RC time constant#Delay (which is more compact and does answer the question).

I don't see any discussion of why this page is protected: why is it so? If there is no known reason then it should be unprotected. This is a wiki. --92.20.173.219 (talk) 14:18, 15 December 2020 (UTC)

 Done as to the link change. The page was indefinitely semi-protected in 2017 following a request at RFPP after an extended period of pending-changes protection. Both were due to years of ongoing vandalism to this article. If you'd like to request that we try unprotecting the page, you're welcome to make a request at WP:RFUP (since the protecting administrator doesn't seem to be very active anymore). ‑‑ElHef (Meep?) 14:59, 15 December 2020 (UTC)

Simple English

Can anyone provide a Simple English page for RAM? Cuahl 16:51, 12 Jun 2005 (UTC)

RAM is like a pencil and paper for your computer to write out it's equations before it does the actual work of solving a problem or writing to the hard drive. RAM is sometimes considered part of the CPU not separate "CPU cache"urName (talk) 04:29, 1 April 2011 (UTC)

Registers are usually part of the CPU or MPU. Cache Ram(Hidden Ram) is sometimes on CPUs either on the die (Silicon chip). Sometimes in a Hybrid Package (ie Pentium slot processors) or on the motherboard. Yes I know Cuah published this in 2005. But some other people may be interested — Preceding unsigned comment added by VladMaster99 (talkcontribs) 17:39, 14 February 2021 (UTC)

Semi-protected edit request on 29 December 2021

The page links to SRAM early on, but does not make the equivalent link to DRAM. I would like to update it to point to the existing DRAM article (https://en.wikipedia.org/wiki/Dynamic_random-access_memory) in the same sentence where the SRAM article is linked the first time here: "The two main types of volatile random-access semiconductor memory are static random-access memory (SRAM) and dynamic random-access memory (DRAM)." WikiWikiGrow (talk) 18:39, 29 December 2021 (UTC)

 Done Signed, I Am Chaos (talk) 19:41, 29 December 2021 (UTC)

Shadow RAM

Shadow RAM is RAM whose contents are copied from read-only memory (ROM) to allow shorter access times, as ROM is in general slower than RAM. The original ROM is disabled and the new location in the RAM is write-protected. This process is called shadowing.

As a common example, some BIOSes have a feature labeled “use shadow BIOS” or similar in the configuration options. When enabled, functionality that would rely on reading data from the BIOS’s ROM chip instead makes use of the RAM installed in the system. Depending on the system, this may or may not lead to a performance boost for calls to the BIOS. With operating systems such as Microsoft Windows, such a performance difference can be unnoticeable due to the way those systems manage BIOS functionality and through their use of different ROM routines.

Shadowed memory cannot be used for any other purpose and as a result less extended memory is available to systems which have it enabled. On most modern systems, the feature can be toggled in BIOS settings.[1]

Linux does not use ROM BIOS routines, so disabling Shadow BIOS in motherboard settings will free up a small amount of RAM (about 200 kB) [2]

References

  1. ^ "Shadow Ram" (HTML). Retrieved 2007-07-24.
  2. ^ "Optimizing Linux Memory Usage" (HTML). Retrieved 2007-08-09.

Matched pair

What about some info on what a "matched pair" is? --Anonymous

There is a short note on this in the DDR SDRAM article, but it could do with more detail. One contributor remembers them being used in old Macs, too. If you find out anything, please help us by adding it to Wikipedia. -- Heron 17:59, 20 Aug 2004 (UTC)

A see also section

It needs one.

I've appended this section based on the one from SDRAM as it seemed very inconsistent to have links to different kinds of memory only from other types of memory and not their parent. Amend as you will!