Nvidia is currently working on implementing PhysX into its CUDA language, which is supported by all GeForce 8-series GPUs. When this is ready to go, Alibrandi said that owners of these GPUs will ‘simply need to download the CUDA PhysX drivers from Nvidia,’ and that ‘hardware acceleration will then be transparently supported for applications making use of the PhysX SDK.’
http://www.custompc.co.uk/news/602205/nvidia-offers-physx-support-to-amd--ati.html