For NVIDIA's PhysX technology, it has been a roller-coaster ride since NVIDIA's acquisition of the technology, and its makers. As much as PhysX quickly became one of the important selling-points of NVIDIA's consumer graphics line GeForce, it also had its small share of controversy, linked to market dynamics more than anything. With the technology's port to the GeForce GPU, enthusiasts fancied having the freedom of choice with a primary GPU that is dedicated to rendering 3D graphics, and a second GPU that is just about powerful to assign as a dedicated PhysX GPU.
Although having a powerful ATI Radeon GPU aided by a less-powerful NVIDIA GeForce GPU for PhysX was possible on Windows XP, the succeeding Windows Vista restricted this, by making sure two active display drivers couldn't coexist. Windows 7 removed this restriction, but before you could rejoice, NVIDIA quickly released a driver-level code with its 186 series drivers, that disables NVIDIA PhysX altogether when a GPU from another vendor is coexisting and enabled, even an IGP for that matter. If that wasn't bizarre enough, with the latest drivers, you can't even pair an Ageia PhysX PPU card with an ATI Radeon GPU going about its business. To the rescue comes a soft-modder's nifty bit of software that overrides this restriction from NVIDIA's drivers, so you can use dedicated GeForce PhysX cards on machines with ATI Radeon primary GPUs again. The corrective driver patch comes from tech portal NGOHQ.com community member GenL.
The patch, which you can download here, has been successful so far going by community members' feedback. It lays to rest any argument NVIDIA would like to make about how using dedicated PhysX cards with primary GPUs of your choice (which happen to be an ATI Radeon) would be the end of the world, other than of course, market-dynamics.
Speaking of which, here's NVIDIA's statement on why dedicated PhysX accelerators ought not to work with GPUs from other vendors: "PhysX is an open software standard any company can freely develop hardware or software that supports it. NVIDIA supports GPU accelerated PhysX on NVIDIA GPUs while using NVIDIA GPUs for graphics. NVIDIA performs extensive Engineering, Development, and QA work that makes PhysX a great experience for customers. For a variety of reasons - some development expense some quality assurance and some business reasons NVIDIA will not support GPU accelerated Physx with NVIDIA GPUs while GPU rendering is happening on non- NVIDIA GPUs."