I am getting a 4850 from a friend to replace my GeForce 7600 GS.
He said that instead of just tossing the 7600, I should leave it in and set my system up so that the 4850 runs the games and the 7600 runs the physics.
Not on a geforce7 card but go ahead and keep the 7600gs for when you need a spare. To run physx it needs to be a geforce8 with 256mb or better. You won't miss much with out physx unless you are playing mirrors edge.
you should keep it just in case anything happens with the 4850 but it won't work
the 2 cards need to be from Nvidia since Ati doesn't use PhysiX
I think it uses Havoc or something