Physx issue

[tomhardcore]

Okay so I have 2 GTX 275's, one is 896MB and the other is 1792MB. I have SLI enabled but for the Physx part there's a problem. I can't choose what card I want to run Physx and Physx doesn't work in games or 3D mark vantage. Specs are vista 64bit, sli GTX 275, 8GB memory, EVGA 780i ftw motherboard, 500gb harddrive. I tried reinstalling the drivers and the physx software but I get nothing. Any help would be appreciated

 

[Mousemonkey]

With only two cards you can't choose which one to dedicate to physx, just enable the option click 'apply' and you're done.

 

[tomhardcore]

That's strange because when I had SLI 9800GTX+ I could pick which one I wanted to do PhysX.