NVIDIA doesn't let me use PhysX in it's own card as long as there's an AMD Card connected in the PC! : r/pcmasterrace
NVIDIA's PhysX 5.0 supports FEM for material physics on the GPU and counters AMD's FEMFX program library for physics via CPU multithreading | igor'sLAB
YES you can use PHYSX on AMD gpu's/Here's how BORDERLANDS PRE-SEQUEL 2014... - YouTube