Both NVIDIA and ATI graphics processors are based on a unified architecture with programmable stream processors that can handle not only traditional graphics (vertex, geometry, texture) processing but also general purpose computing operations. However, NVIDIA have an ace up their sleeves that currently gives them an edge over ATI and that ace is called PhysX. PhysX is NVIDIA's proprietary technology. Only NVIDIA graphics cards are capable of accelerating games and applications that support PhysX. This gives them an important leverage over their competitor, ATI, who has made a remarkable comeback on the back of their Radeon HD 4000 series of graphics cards. As popular as the current ATI graphics cards, they cannot accelerate games and applications that support PhysX. But just how important is PhysX acceleration? That's what we are about to find out! Link : The NVIDIA PhysX Tech Report
Quite honestly, I disagree with NVIDIA's implementation of PhysX. Intel, AMD/ATI are all moving in the direction of OpenCL which Havok will ultimately run off of (and that would run off of NVIDIA hardware too). All things considered, would devs want an SDK that will only run on NVIDIA hardware, or a SDK that will run on all hardware?
IMHO, that's precisely their plan. PhysX is proprietary which means they can control who gets to license it. If they can get enough developers to use their PhysX engine, then eventually it may become the dominant engine and well, I'll bet NVIDIA will only allow their GPUs to support hardware acceleration of PhysX.
so far how many title with PhysX? But if Nvidia's plan works, would that mean the game will be unplayable/crippled for ATI?
And lee brings on exactly what my point is. Would developers want to implement a SDK that limits their own market or a SDK that everyone can use. Obviously NVIDIA wants to play hardball and push their format. But would game developers want to under serve ~2/3 of their paying customers in that sense. That's where OpenCL shines greatly because everyone can use it.
I foresee NVIDIA pushing this avenue (PhysX) all the way, as long and as far as they can, because it is to their benefit. But I believe eventually Microsoft will include it into DirectX, possibly by licensing it from NVIDIA.