[Wine] PhysX support. Driver? Wine?

[J V]

So I'm playing mirror's edge and the difference between enabling and disabling PhysX is massive - mainly due to the fact that it's trying to use my CPU rather than my GTX 680 graphics card.

Installing physx via winetricks made no change to performance so I have to ask: Is lack of working hardware physx support a result of lack of wine support or a lack of nvidia driver support?

(I'm using 295.40 proprietary nvidia driver)