A Reddit user has successfully run FSR 4 on their Sapphire Radeon RX 7900 XTX, despite not being officially supported by AMD. This achievement is made possible by the latest Mesa update for Linux, which enables FP8 precision via FP16 on older GPUs.
To achieve this, the user used the OptiScaler DLL injection tool to force games to support FSR 4. Once that’s done, only a couple of commands are needed, and the user can run the game with FSR 4 enabled. A stable release of Mesa is expected by August, which should automate these patches in the driver.
The user tested three games – Cyberpunk 2077, The Elder Scrolls IV: Oblivion, and Marvel Rivals – and found that FSR 4 delivered better quality than FSR 3.1 and provided better frame rates compared to running at native 4K resolution. However, this came at the cost of a performance drop, especially in Cyberpunk 2077, where the user experienced a 33% decrease in frames per second.
To mitigate this, the user suggested enabling frame generation or reducing quality settings if desired. The results are promising for FSR 4 on the RX 7000 series GPU, but it’s essential to note that performance is still limited due to hardware constraints. This technique may appeal to those who want to push their gear to its limits and experiment with AMD’s latest upscaling tech on unsupported GPUs.
Source: https://www.tomshardware.com/pc-components/gpus/enthusiast-hacks-fsr-4-onto-rx-7000-series-gpu-without-official-amd-support-returns-better-quality-but-slightly-lower-fps-than-fsr-3-1