Prime stable 8+ hours but crashes in 3D....

I'm rock solid stable at 3500 but am trying for more... because well ... why not

Anyways, my system in the sig is prime stable for 8+ hours using the custom option under torture test with ffts of 8-4096 using 800mbs of ram per instance of prime95 at 3600 makeithurts. Whenever I go to launch a 3D app the system craps out. The video card on its own is stable at an OC'd level, but this also happens when the video card is not OC'd.

Are there any particular voltages that I should be looking at to help remedy stability?

maybe its your PSU... it might not be able to handle the 8800. Does this happen when everything is at stock speeds?

I have been running into the same issue. most of the time the system will lock up right when I start a 3d app, but sometimes it will run for a minute or two and then lockup. I've monitored the voltage, and the temps, and those don't go out of range.

My 7950 Gt does it even when it's no Oc'd.

It only seems to do this when I'm running at over 3.2 Ghz. Ive tested my machine on Orthos over night, (roughly 14 hours) and it was rock solid at 3.4 Ghz. But 3d makes it crap out.

As of yet I haven't been able to nail down the cause. For righ tnow, I've backed my OC down to 3ghz so i can play games.

The PSU is a 700W OCZ ....

Do you back down your memory clocks to reach stability or just your CPU clocks?

Pure guess: write combiners. There are special paths in the CPU, FSB, chipset, and memory interface for dealing with write combined memory. And other than 3D graphics, very few programs will use these paths. So all your other stability tests are missing coverage of potential speedpaths.

It's possible you may need some more voltage to run the 3D benches than the torture tests. Have you tried feeding the CPU more voltage? What speed/timings is your memory at?

Just a 'touch' more voltage and everything was happy. I gave both a bit more to the MCP (1.55) and the CPU (the stepping above 1.5) and everything played well.


Now just to determine if 150 extra megahurtz is worth going from 1.43 volts at 3450 to 1.51x volts at 3600.

Memory is at 450 when running 3600 and the timings are 4-4-3-5

For a 24/7 clock you probably wont notice the 150mhz.

I'd stay with 3.5. Keep the voltage and your timings low, no need to bother with another 150mhz, which inkfx said, probably won't even make a noticeable difference.