SLI'd physics

[gilljoy]

I've got a quick question, im currently waiting for my GTX570 to arrive in the post and I was reading on the Nvidia website that you can use 2 cards one for graphics and one for physics.

My question is I've got a 7600gs lieing about the house and was wondering wither or not its worth sticking that in along with my GTX 570 to have it do the physics work? or is it not worth it at all?

 

[Lonyo]

The 7600 can't do PhysX.

 

[sxr7171]

I don't really get that either. In the driver settings I set it to auto. So if I have one card is that card handling both graphics and phys-x? With 2 cards I guess one card handles graphics and the other phys-x, but I guess that means I'm not really getting SLI performance. Does this mean I need 3 cards or set it so that my CPU handles phys-x?

With a 570GTX it's less of an issue but with a weak card like the 460 it is concerning. I don't think one 460 can handle 1080p with everything turned up, but the SLI'd setup can assuming both cards are running graphics.

 

[sxr7171]

Okay my answer was in the FAQ:


How does PhysX work with SLI and multi-GPU configurations?
When two, three, or four matched GPUs are working in SLI, PhysX runs on one GPU, while graphics rendering runs on all GPUs. The NVIDIA drivers optimize the available resources across all GPUs to balance PhysX computation and graphics rendering. Therefore users can expect much higher frame rates and a better overall experience with SLI.

A new configuration that’s now possible with PhysX is 2 non-matched (heterogeneous) GPUs. In this configuration, one GPU renders graphics (typically the more powerful GPU) while the second GPU is completely dedicated to PhysX. By offloading PhysX to a dedicated GPU, users will experience smoother gaming.

Finally we can put the above two configurations all into 1 PC! This would be SLI plus a dedicated PhysX GPU. Similarly to the 2 heterogeneous GPU case, graphics rendering takes place in the GPUs now connected in SLI while the non-matched GPU is dedicated to PhysX computation.

 

[Dark Shroud]

Also keep in mind only a few games support GPU PhysX. And in some cases trying to fun GPU PhysX on an old or low power card can actually slow you dont a bit doing more harm than good.

If you're going to buy a card a GTX 460 on sale is probably a good one to get. Since Nvidia hasn't announcted a GTX 560 or GTS 500 series yet. GTS 450s are only a little less than GTX 460s so there isn't much point to buying those.

 

[RavenSEAL]

Again, someone already said above, the 7600GT does NOT support PhysX.

http://www.nvidia.com/object/physx_gpus.html

 

[cmdrdredd]

Another problem is for CUDA. When you run a card for Physx alone it bugs up CUDA in my experience so it can BSOD often at random times during video transcoding or other work.