Fans of older PC games were dismayed to learn that Nvidia had removed 32-bit PhysX and Flow compatibility in its new RTX 50 series graphics cards. However, a new development has brought hope that a solution is at hand.

Nvidia has made the PhysX and Flow SDKs completely open source under the BSD-3 license. While the libraries for these have been available for some time, they were lacking the key source code of the kernels. These have now been made available for developers and modders to tinker with.

Nvidia dropped support for 32-bit PhysX on its latest GPUs, but they could get it back

The PhysX real-time physics engine powers a fair number of older PC titles, including Batman: Arkham Asylum, Metro 2033, Mirror's Edge, and Borderlands 2, among others. Flow is a fluid simulation engine that handles things like fire, gas, water, and smoke effects.

Nvidia decided not to include the 32-bit CUDA on the latest RTX 50 series GPUs, which caused a severe downgrade in the performance of anything using PhysX or Flow 32-bit. One striking example is the GTX 980 Ti beating the RTX 5080 in 32-bit PhysX benchmarks. We also saw people resort to using an older GPU to back up their new 50 series card in a dual setup.

Now, as reported by Tom's Hardware, the custom GPU acceleration technology is available for anyone to use; developers and modders will be able to view, modify, and build on the existing libraries. It is fairly likely that the first task for those developers will be to construct a compatibility layer between the 32-bit and 64-bit implementations to implement PhysX support for older games when using an RTX 50 series GPU.

Though PhysX 32-bit and Flow have largely been superseded by newer technologies such as the Chaos Physics engine used by Unreal Engine 5, there is still a huge backlog of games that many users will want to play that utilize this older technology.

It is possible that brand-new solutions for graphics and animation will come about due to the release of Nvidia’s source code. At the very least, 50 series owners may not need to buy an extra graphics card just to play older games. On top of that, the possibility of bringing the technology to AMD or Intel hardware may also be explored.

About the Author

Rebecca Hills-Duty

Writing and journalism experience at VRFocus, UploadVR, The Escapist, HTC, PC Gamer, Tech Radar+ and Dexerto. Can sometimes be found playing with retro tech.