Hmmm okay. The 640 they have is 2GB. Would that be enough? And how do I dedicate PhysX to that card? I read that it's on the Nvidia control center or whatever under 3D options or something.
EDIT: Since that card would most likely bottleneck the 7950, does anyone have good recommendations for a good PhysX card? I don't want to spend more than $100 because at that point it's just not worth the little things PhysX does.
I would just get an 640 for Physx. That and its 384 CUDA cores should be enough.