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Memtests

jeffiepoo
jeffiepoo asked
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Last Modified: 2013-12-01
I have a computer here - I am running the Memtest 86 V 3.2 bootable cd. I cannot figure if the problem is the MB, or the RAM. I have 2X 1GB chips of PC2-6400 (DDR2-800mhz), and 2X 512mb chips of PC2-6400 (DDR2-800mhz) and four slots on a capable motherboard. The mother board model is P5N32 -SLI SE Deluxe. When I put in just the 1GB chips in either set of ram slots it tests fine - (2X 1GB).  It tests fine with the set of 512mb chips in any set of slots as well. But I have the following questions:  Why will I sometimes get 1 or 2 memory errors one test and other tests it tests just fine? I've never had that before, and I am sure the RAM is fine because I've tested it over and over. It is all the same kind of ram. Could the motherboard be a problem?  Also, the MAIN question is - why does it take 6 times longer to test the 2X1GB chips alone in the system than it does to test the 2X512MB chips?
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You can Try Windows memory Diagnostic test and see if it preforms any better.
http://oca.microsoft.com/en/windiag.asp

Are you doing Extended Tests?

Author

Commented:
There is no option for "extended tests" in Memtest 86 v. 3.2    We will run the tests overnight though. It will pass many times one time, and have a few errors other times. I will try the windows memory diagnostic on the UBCD next to see if that performs any better.   The ram is non-ECC as well
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Commented:
Are both sets of ram rated for the same timings? (like 4-4-4-12)

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Commented:
>>   Why will I sometimes get 1 or 2 memory errors one test and other tests it tests just fine?   <<   this points to bad ram; you sghould have NO errors.  Test each stick separately.
And if you want to use both kinds of ram together, better be sure they have the same timings, as suggested by coral; even then, some boards do not like mixed ram.

Author

Commented:
It is the same brand, exactly the same ram, I am sure the timings are the same although I don't know how to find that out. I appreciate the advice about testing the ram separately, but I need to be able to set everything up in dual channel for anything otherwise nothing will show up on the screen. I will test one set of ram and it will test fine on a 16 hour memory test, then I will test the other ram in dual channel and it will do fine, then as soon as I put it all together it has some errors (like 2 errors), then I will take it out and put in the first set of ram that had previously tested fine, it will have like 1 error.  So then I replaced that origional set and tested the new set and it was fine. Then I put in BOTH sets that tested fine and it had like 6 errors. And like I said - the timing IS the same.   Could it be a MB or BIOS problem? This is driving me crazy, what should I do?
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Commented:
>> I am sure the timings are the same although I don't know how to find that out

<fast and dirty way>
Is there a C and a number at the end of the PC2-6400 (should be a 3,4, or 5)
What brand of ram?

Another thing is that some mobo's will down clock the memory bus when using dual dual channel.
The bios or the ram might be having trouble switching the speeds around.
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Commented:
it can be a mobo problem, with the memory controller
>>  but I need to be able to set everything up in dual channel for anything otherwise nothing will show up on the screen   <<   i 've never seen this behaviour before - what mobo do you have?  they all work with/without dual channel imho

Author

Commented:
Hey guys, the MOBO I have is in the original post.

The answer that I figured out is: The MOBO has a specific list of successfully tested memory that I should use
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Commented:
no one suggested that til I figured it out, good job commenting at the end nobus.
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