Is there any evidence you can provide for this? I don't necessarily dispute it, but I don't entirely buy that it's just for rendering - I thought some games were starting to offload particle systems and physics.
This is regrettably true. PhysX is an Nvidia technology and, as I understand it, is supported to run on Nvidia GPUs. The consequence is that developers who are faced with this option will quickly realize that it'll be easier to just run the same tech on a user's machine regardless of which GPU solution they have (Nvidia, AMD, Intel) and optimize their game the same way for all platforms.
Can I use an NVIDIA GPU as a PhysX processor and a non-NVIDIA GPU for regular display graphics?
No. There are multiple technical connections between PhysX processing and graphics that require tight collaboration between the two technologies. To deliver a good experience for users, NVIDIA PhysX technology has been fully verified and enabled using only NVIDIA GPUs for graphics.
Yeah unfortunately. Both UE4 and Unity use the CPU versions of PhysX. If your game runs on console, it will be running on an AMD gpu, which doesn't support GPU PhysX.
Some games (many actually) are using gpu accelerated particles, but they're pretty much purely for rendering.
Remember that frame times are super tight on games (16 and 33 ms per frame for 60 and 30 FPS respectively), and consoles are notoriously underpowered.
Working in games, none of my colleagues or companies we work with have much interest in offloading physics to the GPU at the expense of rendering performance.
