Tek-Tips is the largest IT community on the Internet today!

Members share and learn making Tek-Tips Forums the best source of peer-reviewed technical information on the Internet!

  • Congratulations TouchToneTommy on being selected by the Tek-Tips community for having the most helpful posts in the forums last week. Way to Go!

Memory Question

Status
Not open for further replies.

BossaNova

Technical User
Nov 6, 2006
17
US
I recently purchased a new Memory stick.. believeing that it would be compatible with the memory I currently have.. This is what it says on the older mem stick : "512mb 64X64 PC3200 CL2.5 DDR" now my system Bios states it's running it at 400mhz at 2.65v okay, The stick I just recieved in the mail is a 512MB 184-Pin DDR SDRAM DDR 400 (PC 3200)next with each mem stick in "solo" - Dimm1 Windows Memory Diagnostics checks out great!! no failures.. when I attempt to put them in Dimm1 & Dimm2 and run windows Mem Diag. it freezes up?? now the two things I find odd are: 1. my old stick states 64X64 which I have no clue what that means. & 2. One stick has mem buffers on both sides and the other only has mem buffers on one side?? Any helpfull advice on this would be greatly appreciated! Mainly just want to know if this new stick is even going to be able to work for me..?
 
There are so many factors involved when you pair up two memory sticks. You would think just knowing that it's PC3200 and has 184 pins is enough, but unfortunately it's not.

The two biggest factors are latency and density. You noticed that one of your DIMMs has memory chips on both sides, while the other has them only on one side. However, both are 512MB sticks of memory. Clearly, you can see how one is more dense than the other. Then there is the "latency" factor. You may have noticed that some DIMMs come with ratings that look something like 2.5-3-3-6. Each number represents a different kind of latency (or time that it takes for the DIMM to read a particular area of memory). The higher the number, the slower the DIMM is. The first timing listed is the most common, known as CAS latency. If you hear someone tell you they have a CL 2.5 or CAS 2.5 DIMM, that's the number they're talking about. The others are less important, but still matter. There's a good chance that the two DIMMs you have vary a great deal from each other somewhere within these 4 ratings.

While the BIOS has no problem adjusting to these differences with one stick, it can have trouble working with two. Look in your settings and see if the DIMMs are running in dual-channel (I don't know what motherboard and CPU you have, but this is a possibility). Unlike the older single-channel mode, dual-channel is even more demanding on the memory controller. Slight differences between the DIMMs can wreak havoc. In this mode, it is recommended that you use identical sticks from the same manufacturer or disable dual-channel altogether.

For more info, search on any of the terms I used at
~cdogg
"Insanity: doing the same thing over and over again and expecting different results." - Albert Einstein
[tab][navy]For general rules and guidelines to get better answers, click here:[/navy] faq219-2884
 
When you have 2 sticks of memory in one computer the BIOS will automatically run the system at the slowest compatable speed of both sticks. Sometimes at a slower speed than either of the 2 memory sticks.

If the latency is different on both sticks, then the computer has to run slow enough to use both.

This is why it is a good idea to use the same exact memory modules in a PC when you use more than one memory module.

It is very difficult to answer a question like this because every motherboard runs a little differently. Also sometimes on some motherboards, using a different BIOS version can make the memory sytem work better. It is quite common for a motherboard manufacturer to realease a new and improved BIOS version to fix memory problems. Also some motherboard models had problems with memory or preferred the RAM to be in a specific slot or had some other compatiblity issues only for that specific motherboard. So it is difficult to give a difinitive answer.

When purchasing RAM or memory Modules (STICKS), I recommend going to the motherboard manufacturer's website and looking up the compatability list, or using a similar service provided by the Memory Manufacturer's website. If the RAM Manufacturer certifies the RAM for your exact motherboard Model, then usually they guarantee it.


If you do not like my post feel free to point out your opinion or my errors.
 
Thank you, Everyone so far all your advice has been helpfull!! I've done what I should have done in the first place: Researched the company that manufactured the original Ram Module which was "Legacy Electronics" found the exact duplicate [via-part#] of the module I already have and requested a qoute.. I had 2 before one went down.. worked good might as well try to get that back..lol Everyone's Replies have been quite informative and any other information they'd like to pass my way is greatly appreciated! as for the OCZ Ram module I'm going to return it thats if Newegg will take it.. they should I've only had it in my pocession 36 hours so far..

BossaNova
 
Glad to hear you got that sorted out. For the record, OCZ is a top-notch brand and probably isn't the DIMM that is causing the motherboard to throw a fit. However, ditching it in favor of buying another Legacy Electronics DIMM is a reasonable choice at this point.

~cdogg
"Insanity: doing the same thing over and over again and expecting different results." - Albert Einstein
[tab][navy]For general rules and guidelines to get better answers, click here:[/navy] faq219-2884
 
Ya.. I've bought OCZ for another system I built a few weeks back.. and it runs awesome.. I got dual channel ddr2 2gb 2x1gb modules yeah I agree OCZ is a great brand.. I'm not a 100% as to whether I'm goig to send it back completely yet I might just decide to keep it for inventory reasons.. I'm not quite sure about Legacy Electronics at this point .. their customer service is starting to reflect to me thier standards I wrote them 2 days ago and told them I needed a reply ASAP.. and still I have not heard nothing back..which is kinda sad.. if this keeps up I might just decide to buy another replica of the OCZ mem module and put this other Legacy chip in the closet..lol So everyone.. if you buy Legacy electronics Mem Modules I would'nt plan on getting much more than about 5-6 years out of them.. we'll at least that was my case..
 
Status
Not open for further replies.

Part and Inventory Search

Sponsor

Back
Top