Users don't necessarily need the Radeon RX 9000 GPUs to use AMD FSR 4, as the DLL accidentally supplied by AMD is doing the job decently.

AMD's Mistakenly Released FSR 4 Int8 Files Can Help Enable FSR 4 on RDNA 3 and Even RDNA 2 and RTX 30 GPUs on Windows; Users See Massive Upgrade in Visual Quality Over FSR 3.1

Last month, AMD accidentally released the full source code for FSR 4, its latest upscaler that offers significantly improved visual quality over FSR 3.1. Unfortunately, the technology only works with RDNA 4 GPUs, aka Radeon RX 9000. Even though AMD did officially release the latest update for Adrenalin software for running FSR 4 in games that already ship with FSR 3.1 natively, one cannot do it unless they own an RDNA 4 GPU.

I got it working, 7% performance delta in CP77 at 14

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