Prime95 fails without overclock

[jjz]

Hi all- I noticed my computer had recently started crashing especially during video encoding. I fired up prime 95 (v25.6) and noted the following:

Prime95 testing:
Using blend- the computer crashes and reboots within 1 minute
Using small FFTs it can run at least one hour without problems (too impatient to run longer)

I ran memtest which showed no errors after one pass (again too impatient).
Temps on all four cores stay below 60 during prime testing
FYI- all the above was at stock settings -This build had been running without problems (prime tested) overclocked at 3.3ghz for ~3months previously.
What do I do next to troubleshoot?

System details:
CPU- q6600 G0
Board- Gigabyte ds3-l
Memory- OCZ DDR2-800 (OCZ2G800R22GK)
powersupply- antec truepower trio 430w
windows pro sp2

thanks

 

[robisbell]

run memtest86+ for 6 hours. report back the results. get a multimeter and manually test the PSU's voltages with and without a load, report back the results.

 

[JustaGeek]

Set your memory voltage manually in BIOS (I believe to about 2.1V for OCZ DDR2 800).

Do the same with the timings and frequency.

 

[DSF]

Originally posted by: JustaGeek
Set your memory voltage manually in BIOS (I believe to about 2.1V for OCZ DDR2 800).

Do the same with the timings and frequency.

Yeah if you haven't already I'd double-check the settings on your RAM. It may be that the DS3L is leaving the voltage at 1.8-1.9 when the OCZ kit would like to have 2.1V.

 

[jjz]

I will try upping the memory voltage.
I let memest run overnight- woke up to find no "errors" but the computer was completely locked up/unresponsive-- will test the power supply this AM
thanks

 

[robisbell]

okay, if it froze while running memtest86+ thats not good, no telling when the lockup happened, but I have a feeling it's the ram, but will await the PSU test results.

 

[jjz]

Wow- it looks like upping the memory voltage did the trick- will do further testing tonight but just ran prime95 blend test for 2 hours without problems (before it lasted a total of one minute!). Looking back I think I had always had the memory voltage upped slightly but when I went to troubleshoot I loaded the "optimized" defaults which only fed the ram 1.8v. Will let you know if this really solved the problem tomorrow AM.

Thanks everyone- ran prime95 for 16 hours without errors- overclocked!! Problem solved!