Officially, FSR 4 only runs on RDNA 4 kit, and AMD marketing says you need the latest Adrenalin update to make it work in games already shipping with FSR 3.1. The snag is that unless you own an RDNA 4 board, you are out of luck.

Unofficially, it is a different story. The leaked source code contained INT8 model files, which older cards including RDNA 3, RDNA 2 and even Nvidia’s RTX 30 series can use. A Reddit user going by the handle AthleteDependent926 compiled the files into a working FSR 4 DLL, and now people are swapping it in for FSR 3.1 through OptiScaler on Windows.

On Linux, enthusiasts had already forced FSR 4 onto RDNA 3 cards, though the lack of FP8 support meant the GPUs had to emulate via FP16, dragging down performance. Windows users were previously locked out, but the INT8 models open the door.

Reports suggest the upgrade brings a noticeable leap in image quality, though at a cost. Frame rendering time can triple, and frame rates are typically 6-7 FPS lower than FSR 3.1. Still, players say the trade-off is worth it. One Cyberpunk 2077 user with an RX 7900 XTX reported shimmering grass finally looked decent at 1440p with ray tracing on, despite the frame rate dip.

Balanced mode appears to offset much of the performance loss while still delivering visuals superior to FSR 3.1. The catch is that OptiScaler is required, and the trick only works in single-player titles.

AMD has not commented on the leak, but given the community is already putting FSR 4 where it was never meant to be, it may not have much choice but to live with it.