That’s misleading in the other direction, though, as PhysX is really two things, a regular boring CPU-side physics library (just like Havok, Jolt and Bullet), and the GPU-accelerated physics library which only does a few things, but does them faster. Most things that use PhysX just use the CPU-side part and won’t notice or care if the GPU changes. A few things use the GPU-accelerated part, but the overwhelming majority of those use it for optional extra features that only work on Nvidia cards, and instead of running the same effects on the CPU if there’s no Nvidia card available, they just skip them, so it’s not the end of the world to leave them disabled on the 5000-series.