Prime95 woes!

I am new to overclocking and have been making an attempt at it.

I have been trying to lower the latency settings on my Corsair XMS PC3500 512MB sticks (total 1 GB ) from their default of 2.5-8-3-3 to something more aggressive like 2-6-2-2. So far whenever I run Prime 95 it always craps out on me after a few minutes at the more aggresive memory settings.

I have an Abit IC7-G mobo with the latest BIOS.

I increased the Vdimm from the default setting of 2.6 up to 2.65.

That did not help. I then proceeded to increase the Vdimm from 2.65 up to 2.7. Once again that did not help. My only option is to try more voltage (only option left is 2.8v) or to let up on the timings.

The two sticks are running in Dual DDR mode and they are not TwinX. The winbond Hardware doctor program that came with the mobo reads DDR temps acillating between 2.65-2.67v. I think that if I leave the Vdimm at 2.7 that it should be OK. I would love to hear from anyone that has a similar setup how successful they have been and suggestions for me to try.

Also please let me know if running my memory at Vdimm of 2.7 v is safe, I really don't want to destroy the sticks , they cost me an arm and a leg.

If 2-6-2-2 is unobtainable is it better to go with 2-7-2-2 or 2-6-3-3?

Anyhelp is as always appreciated!

I run my Corsair 3500's at 2.8 voltage @ 2-5-2-2 all the time, so the voltage for you should be okay. Lots of people here run their RAM @ 2.8. What speed are you trying to run the RAM at?

Right now I'm just trying to run the Ram at 200mhz ( DDR 400 ) the default. Have you passed successfully the Prime95 torturetest? I can run the ram at 2-6-2-2, my problem is I can complete a successful torturetest. I can playgames at those setings and run benchmarks and burn in tests with Sisoft's SANDRA.

I just can't pass Prime95. Which ultimately means my system is not 100% stable.

Have you passed Prime95? If so how long did you let it run for?

Thanx for the reply.

Yes, I can Prime95 until the cows come home. As long as you're stable in games & in every other normal operation you use your machine for, I would't worry too much about Prime95. My last machine would crash in Prime95 in less than 1 minute but was rock stable in every other app & I never had a problem with it other than Prime95. Can your RAM pass all the memtest86 tests? If so forget about Prime95.

Thanks Tikal for the info,

I ran the Memtest-86 program and started to get errors on test #5. So I started to play around with the memory settings to find what works with no errors.

The best I was able to
do is 2-5-3-2. Thats not to bad if it's stable. My benchmarks under Prime95 went from 9.63 ms on the 256 FFT under 2-6-2-2 (unstable) to 9.67 ms with the 2-5-3-2 setting.

Right now I'm running the Prime95 torturetest to see if it will be stable at the 2-5-3-2- settings. I hope that it will.

My current Vdimm is at 2.65 v and I think I will keep it there untill necessary since raising it thus far has not helped with the memory stabilization prob's.


Thanx as always!