Talk:DIMM

Terminology
Hi. Thanks for the explanation. I still don't understand what is "dual" about the dim, nor do I understand what is "in line" about it. Is the DIMM "dual" because it carries information on each side of a pin? I am trying to understand what makes a DIMM, different than a SIMM. Thanks for any help you can provide. —Preceding unsigned comment added by 138.88.66.226 (talk • contribs) 0:20 UTC, 14 February 2005
 * the major difference between simm and dimm is that simm can work on single line that is it can work on one side of the ram whereas dimm which is dual in line memory module can work on both sides of the ram.
 * sub:varun verma —Preceding unsigned comment added by 202.164.55.50 (talk • contribs) 08:30 UTC, 20 June 2005

hello my name is siby. i whish you include the speed of DIMM used in computer system.

I added an explination of the differences between DIMMs and SIMMs. And I think this article has enough information that we can remove the stub status. Any objections? --Pboyd04 20:42, 26 December 2005 (UTC)

Pin layout
Does anyone have references for the pin layouts and method of operation of the different types of DIMM? It would certainly be useful to address this topics. JulesH 11:17, 13 October 2006 (UTC)
 * you 're right. i have inserte the package gorm of 168 pin (13 cm and 2 holes), i'd like to see others version too. --83.190.155.53 17:10, 12 September 2007 (UTC)

ps i was looking for package list and i found this page (sorry this is a commercial site but i haven't found a free site yet)  —Preceding unsigned comment added by 83.190.155.53 (talk) 17:16, 12 September 2007 (UTC)

As far as I know DIMM SDRAM memory has 184pinn,and one hole in the center. The 2 holes might be DDR SDRAM. —Preceding unsigned comment added by 71.206.65.120 (talk) 22:21, 27 March 2009 (UTC)

DDR1 and DDR2 Speed
In the speed section can you clarify the difference between the speeds of DDR1 and DD2... is the strobe at the same speed as the data and twice the clock in both cases? ...

DDR1 ...have data but not the strobe at double the rate of the clock. i.e., PC1600 = 200 MHz data & strobe / 100 MHz clock for address and control .... DDR2 ... also (?) have data and data strobe frequencies at double the rate of the clock. i.e., PC2-3200 = 400 MHz data & strobe / 200 MHz clock for address and control .... Jnwisner 16:45, 14 July 2007 (UTC)

Memory module description in EEPROM chip
I miss a notice that most DIMM modules carry a small EEPROM chip that describeS specification of the module (capacity, timing, manufacturer, etc). And I miss a detail article about this EEPROM chip, that is accesible at I2C bus on most cases as I know. Information from the chip can be read with Z-CPU freeware under Windows, for example. BIOS process the information from EEPROM chip too to configure system to optimal values during computer boot.

Well, I found the article about SPD: Serial_Presence_Detect —Preceding unsigned comment added by 89.24.36.147 (talk) 11:12, 27 January 2008 (UTC)

Am I wrong or is this whole section plain wrong? There's DIMM SDRAM,and DDR SDRAM; a big difference! It seems they mix it up a bit! DIMM SDRAM = supposed to be 184 pin, one hole on the bottom, 2 holes on the sides, and speeds ranging somewhere like 66 to 100Mhz. (It might be possible that 33Mhz or 133Mhz exists too). DDR speeds usually go higher then 100Mhz. —Preceding unsigned comment added by 71.206.65.120 (talk) 22:24, 27 March 2009 (UTC)

MicroDIMM?
Given that there's no definition of exactly what a MicroDIMM is, in what devices it is used, etc., I have a hard time understanding why MicroDIMM redirects here, other than the fact that the word is on the page. Anyone care to add a description? —Preceding unsigned comment added by 67.91.44.34 (talk) 15:53, 6 March 2008 (UTC)

My laptop has a MicroDimm slot fare as i know its used for more memory all u know at the moment but will keep u informed if i find out much more :) J M F Daddy

Other DIMMs than mainstream?
What about DIMMs used e.g. in printers, set-top boxes, cisco router, etc. pp.? Not even mentioned here... I don't have any information about them but they occur mostly in powerpc appliances and are equipped with sdrams as well as with normal drams. —Preceding unsigned comment added by 79.196.219.73 (talk) 19:39, 22 June 2009 (UTC)

Yes, other DIMMs
I worked as atech for Computer City and ran into regular sized 144-pin DIMMs several times. They were basically mirrored 72-pin SIMMs, if you put them into the computer only half the RAM is available. I remember Canon desktop computers used those and the memory slots could interchange 72 and 144 pin variants. There was another brand, I think it was UMAX MAC clone (at that short time that Apple was licensing their OS). Apple had eprom DIMMs for Mac ROMs. Shjacks45 (talk) 20:02, 16 March 2012 (UTC)

Ease of installation comparison
Add a comparison table of ease of installation, e.g., in http://www.wikihow.com/Install-RAM
 * Press gently but firmly until the clamps close completely. You may need to push the clamps in toward the chip, but do so very gently. If the chip does not fit, do not force it.

Perhaps other designs are easier for the user.... Jidanni (talk) 02:16, 17 July 2012 (UTC)

The description for DDR3 and DDR4 is basically the same.
I'm no expert, but this seems weird. Surely it should be quadruple the clock speed, and not just double? I don't feel certain enough to edit, but if someone else knows anything about it this should at least be clarified. — Preceding unsigned comment added by 192.76.8.18 (talk) 12:22, 25 August 25 2014 (UTC)


 * Hello! Actually, DDR(1), DDR2, DDR3 and DDR4 all perform at double the rate of their clocks.  The n in DDRn serves as a generation designation. &mdash; Dsimic (talk | contribs) 03:44, 26 August 2014 (UTC)

Registered DIMMs
The term/concept "registered DIMM" is used and not explained.

"JEDEC decided that the terms "dual-sided," "double-sided," or "dual-banked" were not correct when applied to registered DIMMs."84.55.110.220 (talk) 08:55, 10 March 2015 (UTC)


 * Hello! Please see the  section above –  it contains a link to the Registered memory article, which explains the whole concept.  In Wikipedia articles, it is a common practice not to link the same term multiple times, so "registered" isn't linked more than once. &mdash; Dsimic (talk | contribs) 10:18, 10 March 2015 (UTC)

Concerning section: 168-pin SDRAM
I don't know if it's me, but I can only see one notch on the bottom edge...

Also, just to clarify, the notch is the thing that makes it impossible to but it in the wrong way or to put in a module not designed for the slot at all, right? — Preceding unsigned comment added by 84.55.110.220 (talk) 09:06, 10 March 2015 (UTC)


 * Please make sure you're looking at the right image; File:DIMMs.jpg (which is visible at the top of the article) shows a 168-pin SDRAM DIMM, which clearly has two notches. You're right, the notch is the mechanical characteristic of a DIMM module's edge connector that makes it impossible to mismatch memory types. &mdash; Dsimic (talk | contribs) 10:24, 10 March 2015 (UTC)

Physical Dimensions
Hi. The height in mm is given.. but not width! Seems like a basic and fundamental part of wiki page on a physical form factor.. any idea why the widths for the various options are not included? The height and width exact measurements were the main 2 pieces of information sought on the page.. Thanks.
 * Good point. I've just added the lengths for regular and SO DIMMs. Please make sure you add a new section at the bottom of the talk page. --Zac67 (talk) 09:38, 13 May 2021 (UTC)

Requested move 24 March 2022

 * The following is a closed discussion of a requested move. Please do not modify it. Subsequent comments should be made in a new section on the talk page. Editors desiring to contest the closing decision should consider a move review after discussing it on the closer's talk page. No further edits should be made to this discussion. 

The result of the move request was: not moved to the requested title at this time, per the discussion below. Dekimasu よ! 03:41, 31 March 2022 (UTC)

DIMM → Dimm – Over the past 25+ years dimm has become a noun for memory modules and is listed in dictionaries, no longer just an acronym describing individual JEDEC standardized memory modules&#32;KelleyCook (talk) 12:42, 23 March 2022 (UTC)
 * This is a contested technical request (permalink). GeoffreyT2000 (talk) 04:59, 24 March 2022 (UTC)

The discussion above is closed. Please do not modify it. Subsequent comments should be made on the appropriate discussion page. No further edits should be made to this discussion.
 * Can you provide some sources to back up that's it's the new WP:COMMONNAME? -Kj cheetham (talk) 14:01, 23 March 2022 (UTC)
 * Contested: Not a good idea, or at least requires discussion. DIMM is "dual in-line memory module", as contrasted with SIMM, and should be consistent with the SIMM article (at least in the absence of strong evidence). —&#8288;&#8202;&#8288;BarrelProof (talk) 17:01, 23 March 2022 (UTC)
 * Oppose – DIMM is correct and by far the dominant form. --Zac67 (talk) 07:39, 24 March 2022 (UTC)
 * Oppose – Ngram doesn't indicate the generic term is gaining over the acronym. Wiktionary says it's just an Old English form of dim. – wbm1058 (talk) 18:07, 24 March 2022 (UTC)
 * Oppose: no evidence presented that the casing has changed in common usage. -- Mikeblas (talk) 15:58, 26 March 2022 (UTC)

SO-DIMM
Do you think it would be beneficial to add wording that "SO"-DIMM means "small outline dual inline memory module"? Nowhere in the article is it explained what the SO stands for.

I could add it but would it require references?

Aethalides (talk) 20:03, 25 November 2022 (UTC)


 * Read again: A SO-DIMM (pronounced "so-dimm", also spelled "SODIMM") or small outline DIMM... --Zac67 (talk) 20:14, 25 November 2022 (UTC)

DDR2 Memory Clock
The table for clock rates of Memory vs Bus Clock vs Transfer Rate seems incorrect, at least for DDR2. According to https://en.wikipedia.org/wiki/DDR2_SDRAM, the Memory Clock goes from 100 to 266 Mhz, while the Bus Clock is doubled (and the Transfer Rate is doubles again... ie, something like Tranfer Rate [MT/s] = 4[MT/s / Mhz]× Memory Clock[Mhz]).

This makes sense as fabricating DRAM chips with ever higher operating frequencies was notoriously difficult (which is the basis for the design of modern CPUs, "latency-hiding").

I'm fixing it.

Then I'll take a look at DDR3 - DDR5 (to make sure, at least, that it's consistent within Wikipedia). nachokb (talk) 02:25, 11 June 2024 (UTC)


 * DDR3/4: according to https://en.wikipedia.org/wiki/DDR3_SDRAM#Modules, Memory Clock remains between 100Mhz and 266Mhz; Bus Clock is 4×, and MT/s is 8×; DDR4 is similar but reaching higher clocks. nachokb (talk) 02:32, 11 June 2024 (UTC)