yeah it has been settled that DX11 is more important than PhysX but i Want to take into consideration Cuda and stream, I know that most gpu accelarated programs use open cl or microsoft direct compute but which is more widespread Cuda or Stream?
(by the way I'm not going to spend 150 euros on any software)
actually, DirectCompute and opencl are not used much since they are relatively new, though expect to see it used much more than CUDA and Stream as they are both cross-vendor, and opencl is also cross-platform.
Between Stream and CUDA, i would say CUDA is used much more often, since NV marketed the crap out of CUDA. Also, i found CUDa just a tad bit easier to develop for than Stream