Physx and Games

[KnoVolt]

So I just purchased Mafia 2 from steam sales, and tried to max it out including putting their APEX Physx on to high. When I turn physx on (even at low), the games greatly dips in fps all the way down the like 20.

I have a more and sufficient rig for the game, so wondering what was going on. I tried to download Physx drivers? But, the installer said mine was already more updated than the one I'm trying to install (the driver was released September 2014).

So what is the problem, I remember having the same issue with Metro and their Physx, but it was solved when I downloaded the driver for it.

Thanks.

Specs:
4770k
GTX 770 2GB
8GB RAM
840 EVO

 

[anti-duck]

Have you selected your GPU as the PhysX processor?

 

[KnoVolt]

Thanks anti-duck it seems as though that is supposed to work. My frame rate still lingers around the 20ish fps range but do go up to the 50fps unlike before.

yet I still find it hard to believe a 770 can't max out Mafia II with Physx on...