Slow 2nd GPU

[Nexus]

First up I suppose I'll let you know what my setup is. I have 2x 1080 GTX's and I disable CPU folding (I see very little point using the same electricity for 1/20th of the GPU's crunching ability).

I've resolved my issue, but I just need some clarification as to why what I did fixed it, issue below.

I disabled SLI mode in the Nvidia control panel (checked this multiple times) and ran my first two WU's. The second GPU was a bit slower than the first, but nothing too bad. After the second GPU finished its WU, the new WU ran exceptionally slow. It was saying 9h+ for a 45k point WU, which is very bizarre.

What I did to troubleshoot:

Did a clean install of the Nvidia drivers
Uninstalled FAH (and data) and reinstalled
Reset my overclocks to default
Performed multiple reboots

What was interesting is that the second GPU remained running at more or less idle (viewed in EVGA precision X) and running at a cool 32C while the first GPU was going full bore 95%+ utilisation even after fully uninstalling/reinstalling both the driver and FAH.

After plenty of reboots, double, triple checking I had SLI disabled in the nvidia control panel, I resorted to pulling the HB bridge out one reboot, and like magic, both cards are now chugging away at 600k ppd each.

Is this normal? Do I have to remove the HB bridge every time I want to fold on both GPU's? I thought I would be able to just disable SLI in the control panel and that would have covered it?

Apologies if this has been answered before, but I had a good look around and plenty of google searches later but came up blank. Most recommended doing clean installs of both, but that didn't resolve it in my case.

[foldy]

Folding "should" be independent of SLI or bridge as FahClient does access each GPU independently. Maybe the gpu index settings got wrong. Why do you disable SLI? You can leave it on while folding.

[Nexus]

You can? Most posts I've seen all say to disable SLI. Some people quoting that FAH just plain wouldn't work with it enabled. Granted, I'd never tried it with SLI enabled, so this might be something I can try later. When these 2 WU's finish up I'll put SLI back on and see if it manages to handle it without issues.

Thanks again.

[Joe_H]

Posts where? There might be some older posts on this forum mentioning problems with SLI active, but that was because of problems with certain of the older drivers nVidia released. I don't recall it being an issue anytime in the last few years. It is possible with new drives from nVidia to support these Pascal cards that an old bug has been reintroduced though.

[Nexus]

They were probably old posts, I was just trying to google without taking note of the date.


Good news is though, so far so good, I have SLI enabled, and both are running steady.

Apologies if I've wasted anyones time.

[foldy]

You're welcome!

[Nathan_P]

It can take several reboots to get 2 cards to fold properly, even experienced folders have this issue, especially with the new cards. I've just set up a single 1070 and it took 4 reboots for everything to start working. I agree with foldy, it sounds like the gpu index's got screwed up.