PhysX dadicate

With the games that are currently out there I would say that you in no way shape or forum need to place a mid line card in something like a 650Ti or something along those lines to power the Physx engine within games. I play games that use it and I have a GTX670 and I turn settings up to pretty much the max with Physx on high and have no issues what so ever and I would imagine a 680 being a little better would have no issues as well. Maybe a couple generation of cards from now if there is a game that uses physx and your card isn't cutting it but I feel for now the answer would be no stick to your card and let that money do the lifting for what you paid for it  

If you already have an Nvidia card that can be used for PhysX, then there's no reason not to throw it in as a dedicated PhysX.

However to go out and buy a mid-range card as a dedicated PhysX wouldnt be worth it. Too few games use it and the 680 is powerful enough to drive PhysX on its own.

for what i saw.. in graphic driver, i need the explaination about this setting between GPU and CPU physX.. is it good with CPU to drive physX?

Due to the way PhysX is set up, it has much less of an impact to performance on the GPU than if you ran it off the CPU. So you want to be running off the GPU.

Your GPU is already taken care of physx you don't need to change anything you set physx to automatic and it will default to your nvidia card. your card can handle the load