oh its physX... its just not HARDWARE physx. theres a reason
i made a thread about this issue some time ago.
Less than 10 actual games use hardware PhysX, most just use it in a software only capacity - and to my knowledge, none of them (Except Unreal 3) use it for anything other than fancy effects.
You know, it never affects gameplay or makes the FPS faster, it just triples the amount of debris to ludicrous levels when you shoot a wall. You can shoot the wall and have a mountain of debris come off - but it fades away fast, and the wall never gets thinner or punched right through... the OTHER engines of the games do that, regardless of whether hardware PhysX is on or off.