Folding with SLI enabled and no dummy plug/second monitor!

[chrisk]

Looks like you can now fold with SLI enabled, and one monitor on Vista without a dummy plug. Mine has been folding away error-free and no loss in PPD for about 12 hours straight now in this manner.

This is possible due to the new 190.xx drivers, which allows for Cuda to access single GPUs in an SLI array. I did the following:

1. Used 190.xx drivers from nVidia
2. Enabled SLI (see notes below). Tested with 3DMark Vantage to ensure SLI was working, and saw scaling which seemed appropriate (~15,000 Vantage score to ~25,000 Vantage score).
3. Added the flag "-forcegpu nvidia_g80" to the GPU1 and GPU2 shortcuts. See the screen capture below for an example of this.





4. Disconnected my second monitor, and unchecked the 'Extend my desktop'.
5. Started up both GPU clients, which were previously working on some WUs that night.
6. Verified that both GPUs are folding (temps are 80c on each, and F@Hspy shows the GPUs working on different WUs at different stages).

Notes on my setup, which may or may not be important:
- using Vista 64bit. This works for Win 7 too.
- two GTX 285s on Asus P6T, cards in PCI-E slots 1 and 3
- did not use the SLI bridge. Folding is not limited by the PCI-E bandwidth, and with newer nVidia drivers the bridge is not needed (thanks rjbarker and 3.0Charlie). Just enabled SLI in the nVidia Control Panel
- left Physx enabled in the nVidia Control Panel
- resumed previous WUs that were downloaded. This was a previously working and stable F@H setup, that was non-SLI and used two monitors with the desktop extended on the second monitor, as was previously required. I did not do a new install; I just enabled SLI, undid the extended desktop, unplugged the second monitor, and resumed folding as I did prior.
- drivers were downloaded ~10th of August. They are 190.xx series, and I believe there was one new release since then.
- no big deal, but I set up my anti-virus to exclude the F@H folders (both the Program Files directory for F@H, and the Appdata folder containign the WUs. You probably don't need to do this, but I included this info anyways).
- I did not verify any additional CPU usage, but it does not appear to be any.

Got on to this by looking around the F@H forums, in which there seemed to be some debate so I tried it and it worked. Hopefully this will make folding more gamer-friendly (unless other issues crop up).

[Arinoth]

Glad to hear your sli folding without a dummy plug but you don't need the sli bridge either, that is the more surprising part.

[chrisk]

Originally Posted by Arinoth

Glad to hear your sli folding without a dummy plug but you don't need the sli bridge either, that is the more surprising part.

According to rjbarker the bridge was not needed, so I decided not to use it yet. From my research, the bridge just reduces traffic on the PCI-E bus (this has been the case for some time now in the drivers).

When I rebooted the first time with SLI enabled, I got a notification message saying that the bridge was not detected, but SLI would work anyways but not at optimal settings. The Vantage scores I got certainly supported the notion that SLI was working. I'll probably try the bridge later on anyways, and retest to see if the Vantage scores improve any.

[Arinoth]

Alright, seeing as i probably wont be going that route for several months to go, would be nice to hear what the results are to you as nvidia will probably refine any driver issues (hopefully) with bridgeless SLI.

[Perineum]

Nice for me, I eventually will be doing SLI or Tri SLI here for gaming/folding. Right now I don't want to insult you all by saying that I'm running Tri-SLI at 1600x1200 resolution, heheh.

But I COULD!

[Dwayne]

I can confirm that it is working for me as well on my GTX 295. I found it a pain to switch back and forth in settings and stopped dual folding so this will make starting and stopping a breeze. The only draw back is the heat I get with both GPUs folding... 75C on core 0 and 71C on core 1 doing 787s. And it seems that GPU1 is only doing about 4500 ppd vs the 7500 ppd of GPU0. I will have to investigate that. I have no other instances running but I have not played with the core affinities. I am running the i7 and it seems only core 4 is busy.

Still, it is running 2 instances without the dummy plug, so that is a good thing.

[chrisk]

I was wondering about the folks with GTX 295s. I thought at first that I had lower ppd, but I just let it go and the numbers returned to normal for me. ~9600PPD on each GPU.

This is great for gamers for sure. Looks like Pande is working on getting both GPUs working on a single WU too.

[Jake_HT]

sickkkkkkkkkkkkk

[chrisk]

Anybody else notice that the picture in my first post is gone? I looked in my vbimage host list and several of my uploaded pictures are gone....

[zlojack]

This is phenomenal news!!!