Prime95 failing after 7 hours

[FP]

Hello,

I recently put together a new rig (see sig) and have been testing it for the last couple of days. All tests (SuperPI, memtest86+, PCMark) pass with flying color except Prime95. Prime95 fails the CPU torture test after about 7 hours. I checked the voltages and temps around the time of failure and they are all excellent. Why would Prime95 fail after 7 hours if it just cycles through the same tests?

All my memory (Corsair Value Select) settings are Auto in the BIOS except the command rate which is set to 1T. I noticed that the BIOS was defaulting to a 2T command rate for this memory when set to Auto. Could this be causing the failure even though Prime95 doesn't test much memory?

Any help would be appreciated...

EDIT: Rig is running stock, no overclocking.

 

[Duvie]

What test are you running in prime95?? This could help us point at the component that may be the issue....

 

[FP]

I am running the In-Place Large FFT's test (max. heat, some RAM tested).

 

[ty1er]

are you OCing your system?

 

[FP]

Ack, sorry... No overclocking. Rig is running stock.

 

[Duvie]

I think there is a setting in there for setting amount of memory used. (what do you have set??)...this has been an issue for some...

 

[DerKaiser]

If I had to guess, I would say it's your memory. Try memtest for a while and see if it pops up any errors.

 

[FP]

Thanks for the replies!

Duvie - I have Prime95 set to use 1/2 of my total memory (512M). What are the issues people are experiencing?

DerKaiser - I ran memtest86+ for about 12 hours and didn't experience one error so I think the memory is ok.

 

[Duvie]

Originally posted by: DerKaiser
If I had to guess, I would say it's your memory. Try memtest for a while and see if it pops up any errors.

If this is the case you better let memtest run a bit (more then a few passes) or you may not see it...Better yet let test #5 run 50-100passes and test #6 as well....This will find a memory error faster then letting memtest run for 7 hours which would be like 10 complete psses and it still may not find an error in test #5 which may occur at 20 pass....I know i have seen it...

 

[Duvie]

Originally posted by: binister
Thanks for the replies!

Duvie - I have Prime95 set to use 1/2 of my total memory (512M). What are the issues people are experiencing?

DerKaiser - I ran memtest86+ for about 12 hours and didn't experience one error so I think the memory is ok.

Something about ram too high the program may try to access the HDD and it cant keep up and errors out....Set it like 64mb or leave it the default it was with the program....

 

[DerKaiser]

Does that Prime95 error occur reproducibly?

I know you're not overclocking, but people who are have been avoiding the 1006 BIOS with the A8N-SLI Deluxe. I switched back to the 1004 BIOS after my max overclock went down after flashing to 1006. Perhaps it's just a flaky BIOS version.

 

[FP]

Not sure if the Prime95 error can be repeated. I am currently in the 6th hour of my 2nd test. The first test failed at 7 hours so I am waiting to see what happens. I hope changing my memory command rate from 1T to Auto (2T) will fix the problem. If that doesn't work I will try BIOS 1004. Thanks for the replies!

 

[Duvie]

Usually with that memory issue I am talking baout the errors could be rather random....2hours here 7 hours there, and then a 4 hours....

I would really try to run a 1t command rate...that is a nother issue altogether, but there is a penalty and so running a lower divider with a 1t rate may be as fast or faster then you have it now...

 

[FP]

Duvie... Thanks, I saw your other post saying you ran P95 for over 60 hours. Wow!

I am having a hard time finding out if my memory is supposed to run at 1T. Do you know where I can find this out? I realize the RAM isn't "overclockers" RAM but I found it interested that the Auto setting on my mobo defaulted to 2T.

 

[dannybin1742]

i have this same memory, i know default is 2t, but does anyone know if it will run at 1t?

i'm awaiting a 939 abit a8v and my 90nm 3500+ which shows up on tuesday


is 1t 2t issue voltage related or is it just better ram chips will do it but not the value select

 

[Duvie]

I dont know those answers....try the manufacturers web page....

I believe most all ram is 1t at list in a single channle state, but their could be some dual channel ram sticks sold that may default to 2t...

I have always found that spd timings have been really conservative, and that may be what this is....Auto may detect 2 sticks and revrt it to 2t per the Ram.....

There are enough running Corsair vaule select that should know this...Start a new topic and ask that question...maybe general hardware would be a better place for that...

 

[dannybin1742]

cool i'll do that

hey duvie, what kind of performance difference at default does 2t vs 1t make in dual channel

 

[FP]

Duvie - How much memory do you allot to Prime95 when you run the Large FFT test?

 

[Duvie]

I have never gave more then 64mb.....However I dont test memory through prime95 so I use small FFT to test it since it isolates mainly cpu and very little ram...I use memtest to test ram, and I use S&M 1.5 (now) to test my heat stability....