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How does multi GPU work?
Posted: Fri May 28, 2010 12:30 am
by julianb
Hi all,
I am kind of lost here- I checked several threads but still can not find an answer...
I have a GTX 275 at the moment and would like to buy in addition GTX 470 (or even GTX480). What I do not know is:
1. Do I absolutely need to connect the two cards using a SLI connector or no connection is needed?
2. Can I connect two different cards (GTX 275 and GTX470) via SLI connector?
Thanks a lot.
Re: How does multi GPU work?
Posted: Fri May 28, 2010 12:34 am
by YoonKyung
julianb wrote:Hi all,
I am kind of lost here- I checked several threads but still can not find an answer...
I have a GTX 275 at the moment and would like to buy in addition GTX 470 (or even GTX480). What I do not know is:
1. Do I absolutely need to connect the two cards using a SLI connector or no connection is needed?
2. Can I connect two different cards (GTX 275 and GTX470) via SLI connector?
Thanks a lot.
You must not connect GPUs with SLI, if you want to use a CUDA application, Octane.
Re: How does multi GPU work?
Posted: Fri May 28, 2010 12:40 am
by julianb
Thank you for your response, YoonKyung
So what- just insert the two different video cards in the PCI-E slots on the motherboard and adjust Octane's settings?
Is that it?
Cheers.
Re: How does multi GPU work?
Posted: Fri May 28, 2010 1:24 am
by Krisonrik
julianb wrote:Thank you for your response, YoonKyung
So what- just insert the two different video cards in the PCI-E slots on the motherboard and adjust Octane's settings?
Is that it?
Cheers.
I remember seeing one of the post saying Octane can access different types of GPU. So yeah I think you are good to go.
Re: How does multi GPU work?
Posted: Fri May 28, 2010 3:45 am
by havensole
Yup, dont connect them in SLI. NMake sure that physx is enabled in the nvidia control panel and setup the mult-gpu in the device manager of octane. Pretty easy.
Re: How does multi GPU work?
Posted: Fri May 28, 2010 7:20 am
by radiance
havensole wrote:Yup, dont connect them in SLI. NMake sure that physx is enabled in the nvidia control panel and setup the mult-gpu in the device manager of octane. Pretty easy.
make sure that physx IS NOT enabled
little typo there havensole.
Radiance
Re: How does multi GPU work?
Posted: Fri May 28, 2010 9:41 am
by Amplitude
i'm sorry Radiance but I had the case yesterday when I installed my second gpu:
if PhysX is NOT enabled, Octane doesn't NOT see the second gpu!
I went to a complete drivers reinstall before understanding that the PhysX setting was causing the issue.
Is it a bug?
Re: How does multi GPU work?
Posted: Fri May 28, 2010 10:02 am
by radiance
Amplitude wrote:i'm sorry Radiance but I had the case yesterday when I installed my second gpu:
if PhysX is NOT enabled, Octane doesn't NOT see the second gpu!
I went to a complete drivers reinstall before understanding that the PhysX setting was causing the issue.
Is it a bug?
that's very strange as here it's the inverse.
if we enable physx on our multi-gpu machines here, the 2nd card is invisible... ?!
Radiance
Re: How does multi GPU work?
Posted: Fri May 28, 2010 10:14 am
by Amplitude
I believe you, very strange that the situation can be inversed depending on the rig you use.
My board has an i975X chipset and SLI is not supported, don't know if it helps...
Drivers: Nvidia dev 197.13 + Cuda toolkit
Re: How does multi GPU work?
Posted: Fri May 28, 2010 10:59 am
by julianb
Thanks for the replies, guys...
As to the physx settings- I will try both ways and see what works and what not.
Cheers.