The game does not use PhysX effects like particles.
It uses PhysX for the vehicle physics. Its run on CPU for AMD users.
So it shouldnt be a problem as its lightweight on CPU.

GTX 680 2GB using the latest WHQL driver by Nvidia, not Beta.
2500K @ 4.2GHz
8GB RAM @1600MHz
1080p
Low - Very High.

FPS is around 30 in multiplayer.
FPS is around 40-50 in Infantry Scenario.
FPS is around 30 in Vehicle Scenario.
FPS is around 30 in Air Scenario.

GPU usage never goes above 40%. (Just like Arma 2)
CPU usage is around 30-50%
(Core 0 and 1 being the most active ones above 50% most of the time)