GPU1's PPD drops by 50%?

I have something odd that I can't nail down.

GTX 295 Dual GPU
Nvidia drivers 285.62
Windows Server 2008 R2 (same kernel as Win7), really not important though.
Client: FAH GPU Tracker using GPU2 and SMP clients

When folding on both GPUs, and a bit overclock on the shaders, I get roughly ~8300 PPD per GPU, +/- 500 PPD on GPU2 client non-adv. It stays steady like this for days.

But if *anything* hiccups, GPU1 drops by 50% and it stays that way until I reboot.

What's a "hiccup"? Say a WU errors on GPU0, GPU1 now folds at about 3500 PPD. (I've only had one WU error in the 300 I've done so far)

Sometimes, the display driver has crashed a few times when fracking with the GUI apps like EVGA Precision and other misc apps when folding at 100% GPU on both GPUs. I've downgraded the drivers and the display driver still crashes maybe once a day. This causes GPU1 to drop by 50% again down to ~3300 PPD.

Note, GPU0 is not affected and still chugs along nicely.

And occasionally, like today, it just decides to drop by 50% on GPU1.

Resolution: Reboot. I tried logging out and back in (remember, Vista/7/2008R2 ties the display driver to the logged in user, to be restarted then), nada. Tried stopping the clients. Nada. Even tried putting the machine to sleep. Nada. Only a full reboot of the server will correct it.

I have 3 other GTX 295s here, and I have swapped out two to test. The same thing happens if one of the hiccups happens. So, it's common to either this machine (Intel S3210SH mobo), or the OS.

No, I can't reinstall the OS. It's a server with a number of VMs running (and I can't be down that long).

Very odd.

Are your GPUs both set to "low" priority? Not idle. Have you tried backing the overclock off to stock? Also, I can't speak for server 2008, but does that have aero? If so make sure that is enabled. There is a weird issue with computer performance if you set the windows to run for "performance" and not use aero. Make sure SLI is disabled too.

this is known issue for 295, 50% ppd dropped. (if you use gpuz, you would notice the shader runs at 1/2 speed)
I suffered with 295s too. Only solution is trying different drivers and also search in this forum for some .."patch" that someone posted.

Thanks guys. Tried searching for GTX 295 patch, ppd, combinations, etc. Nada. I'll keep poking.

By default, W2K8R2 disables Areo but yes, there is a "Desktop Experience" that can be installed that gives Areo.

Damn, I was hoping this was a fire-n-forget setup.

setting the nvidia driver in nvidia control panel to prefer maximum performance is a must.

ChasR said:

setting the nvidia driver in nvidia control panel to prefer maximum performance is a must.

Click to expand...

Maximum Performance enables SLI, which I've always disabled (though I see no difference with or without SLI, PPD is always the same).

I think you mean Power management mode, and it is set to Perfer maximum performance already under Global.

Yes I was refering to power management mode, but I certainly didn't make that clear. I'll look and see what drivers I'm running on my GTX295 at home. It's been running almost flawlessly on Win 7 x64 Home.

Before I got rid of my 295, wich was fresh from RMA, it wouldnt fold reliably at anything but stock clocks. But it benched no problem.. I personally think the card is weak, and has a hardware flaw. As I had 2, 1 died. You shouldnt have to worry abut sli, there was a fix from nvidia that allowed you to fold on both gpus while in sli mode. Set your card back to stock clocks, or even a bit under, wich is best, sad to say.