Did you get this running?
I have 2xGTX-295 and Vista Ultima 64 Bit, a Power Supply of 1200Watt and like you I entered a terrible nightmare battle with trying to get cuda to see 4GPU’s.
I have 2 dummy vga plug’s next to 1 HMI montior (over DVI adapter) and a second vga montior (so I can cover all 4 dvi ports) and I spend really a lot time with installing/deinstalling nvidia drivers cards and analysing the registry.
I now have despite all logic (Quad SLI is ON!! The SLI Bridge is in and I have connected only 1 monitior the other 3 dvi ports are empty …no dummy vga plugs)… Cuda seeing 4 GPU’s !!!
however …
It doesn’t seems to really work with 4 because:
the best performance I ever got (boinc) was when cuda was seeing 3 GPU’s only!
AND the first card runs HOT and the second card has a comparable moderate temperature.
I tend to say that with cuda seeing 3 GPU’s the second card was even hotter.
So to summrize: Cuda sees 4 GPU’s now
but it runs only with about 2.5 till 3 GPU’s judge by temperature and performance seen with Boinc… :blink: :wacko
The registry entries (Hardware/Devicemap/video) looks like I have one card in Sli only(might fit to quad sli) but yet it finds 4 GPU’s. (The display offers two connection 1 and 2 wherease on 2 is nothing connected grey)
So it seems that isn’t what is relevant for the cuda GPU’s detection.
Now there is another entry. The PCI occupation:
Here I figured I need to have 4 entries/subfolders in one of this PCI folders:
(System/CurrentControlSet/Enum/PCI/VEN_10DE&… )
4 time 6&…
and there in the subfolder DeviceParameters each has a VideoID
and in each I have a valid VidPnLkgTopology binary blog which has information in it (not everythign zero)
if the VidPnLkgTopology entry is missing or the binary blog contains onlyl zero’s then it will not recognice it. So it seems to me. (see below)
During my installing attempts I figured out that I can already trigger the Cuda GPU recognition Problem when I install 1 Video Card in the second PCI slot only and leave the firt empty!!!
So I worked sort of backward:
-
(SLI disabled, VGA dummy plug’s in, desktop expanded)
-
Install 1 Card in PCI slot 2 and get 2 GPU’s running! This is the hard part especially when you had 2 card installed before…
-
Then install second Card in slot 1…this will lead to several Blue Screens!! (thank’s nvidia ). But you have to work your way through that and keep trying till it starts.and installs the driver proper. I use 190.38 beta
I had to switched to first card as primary montior somewhen then.
Check registry for 4 VidPnLkgTopology entries…(doesn’t matters at the moment if one has all zero’s in it.)
you will still not have 4 gpu… probabily you have only 1 or 2.
- But then the miracle. activate Quad SLI
after reboot I had cude seeing 4 GPU’s
I rebooted again and it were still 4.
Then I unplugged the VGA dummy’s and the second vga monito…
rebooted and I still have cuda seeing 4 GPU’s…
But as I say…it seems to be it’s only useing two and a half GPU’s judge from performance and temperature (and noise) of the cards…
And unfortunatly it burns my first pci slot card that has bad air flow capability in that slot.
And that’s the point where I then resigned into defat. I was so excited about Cuda wanted to start own projects (tat is the reason why i bought 2 card) and I am honestly so dissapointed by this that I buried my plans with cuda.
Next to cuda I enjoy flightsimulator on an older PC (also vista 64)… the main issue there that I had since over 2-3 years was that the display somewhen crashed and did not recover… Nothing worse than when you have sucha crash right before you could finsih your 2 hour flight. This really kills your day I tell you. This issue was ‘solved’ …well not really solved but at least it recovers from crash and you can continue and end the flight…not before lately driver 185.
Nvidia should really start to focus on their SW quality in my opinion. What is the best hardware (nvidia) on the marked good for when you can not use it because their sw is instable or not working?
…
Here is the relevant Info of my Registry. If you belive it or not this makes Cuda recognices 4 GPU’s! I really thing it is because of the 4 PCI entries with full VidPnLkgTopology
DEVICEMAP/VIDEO:
\Device\Video0 \REGISTRY\Machine\System\ControlSet001\Services\VgaSave\Device0
\Device\Video1 \Registry\Machine\System\CurrentControlSet\Control\Video{DEB039CC-B704-4F53-B43E-9DD4432FA2E9}\0000
\Device\Video2 \Registry\Machine\System\CurrentControlSet\Control\Video{42cf9257-1d96-4c9d-87f3-0d8e74595f78}\0000
\Device\Video3 \Registry\Machine\System\CurrentControlSet\Control\Video{28089D7D-B2D4-47C2-B2CA-8D60A99A0B34}\0000
\Device\Video4 \Registry\Machine\System\CurrentControlSet\Control\Video{28089D7D-B2D4-47C2-B2CA-8D60A99A0B34}\0001
MaxObjectNumber 4
SYSTEM/CONTROl/VIDEO:
VideoID {28089D7D-B2D4-47C2-B2CA-8D60A99A0B34}
SubFolders: 0000 (DeviceDescriptions NVIDIA GeForce 295)
0001 (DeviceDescriptions NVIDIA GeForce 295)
Video (Service nvlddmkm)
VideoID {34018717-467E-4D53-97B5-253D9F65B897} SubFolders: only Video (Service nvlddmkm)
VideoID {94A91FAA-CF9E-4AF0-8A85-1E8971E732F9} SubFolders: only Video (Service nvlddmkm)
VideoID {C50E1217-4107-4E52-9907-69162A757C43} SubFolders: only Video (Service nvlddmkm)
PCI:
VideoID {C50E1217-4107-4E52-9907-69162A757C43} (has valid VidPnLkgTopology entry)
VideoID {28089D7D-B2D4-47C2-B2CA-8D60A99A0B34} (has valid VidPnLkgTopology entry)
VideoID {34018717-467E-4D53-97B5-253D9F65B897} (has valid VidPnLkgTopology entry)
VideoID {94A91FAA-CF9E-4AF0-8A85-1E8971E732F9} (fhas valid VidPnLkgTopology entry)
oh and I didn’t make the
LimitVideoPresentSources
DisplayLessPolicy
entries.
The LimitVideoPresentSources leads to slow Windows startup and Crash when you installa new nvidia driver. So no good option.