Originally Posted by Toss3
Can't you just set it via the nvidia control panel?
Yesh, sort of, but if you've got 3 cards in SLI you can't use one of the cards as a PhysX card. You have to bridge just two of them so the third card that's gonna be used for PhysX isn't bridged to the other two. Otherwise the PhysX and gfx load will be shared over all three.
Two GTX480's in SLI and a GTX260 for PhysX is a nice combo. It's how I'll be rollin if I find I need another GTX480.