Does 9800GX2 Support Geforce PhysX?

I have two 9800GX2s in SLi configuratin, and I just installed the driver 177.92, it say offers Physx feature, but in the “setting” of Physx Properties, I can’t select GPU for Geforce PhisX, there’s no such a option, but there should has such a option on the right of the option “Geforce PhisX”. BTY, I’m using Vista 64bit. Any body can help me?

Should I Install CUDA Driver First?

AFAIK CUDA driver shouldn’t be essential for PhysX.

PhyX is written using CUDA, so you certainly need a CUDA capable driver. Just download the Geforce Power Pack linked on the NVIDIA homepage. Those drivers include CUDA & PhysX.