AMD’s FSR 4, a high-end upscaling technology, has made its way onto Radeon RX 7000 “RDNA 3” GPUs thanks to a Reddit user named Virtual-Cobbler-9930. This user has been testing FSR 4 on the Radeon RX 7900 XTX, and the results are interesting, as FSR 4 was initially thought to be exclusive to the newer Radeon RX 9000 “RDNA 4” GPUs. 
The Reddit post discusses performance testing on three popular titles: Cyberpunk 2077, Oblivion Remastered, and Marvel’s Rivals. The tests were conducted on Linux, but the user has also provided insights for Windows users.
To enable FSR 4 on the RDNA 3 GPUs, the user used Optiscaler to inject the necessary DLL files, overriding FSR 3.1 with the new upscaling method. The first test on Cyberpunk 2077 at 4K showed an interesting outcome: FSR 4 delivered an average of 56.28 FPS, compared to 85.06 FPS with FSR 3.1. Despite the FPS loss, FSR 4 produced a much sharper and clearer image, making it a worthy trade-off for those who prioritize visual quality over frame rates. Additionally, FSR 4 achieved higher FPS than native 4K without any upscaling.
However, there are some caveats. In Oblivion Remastered, while FSR 3.1 offered higher FPS, it also introduced visible artifacts. FSR 4 significantly reduced these artifacts, albeit at a 20-30% performance hit. Users can tweak settings, such as using FSR’s balanced mode or enabling frame generation, to boost FPS without compromising image quality too much.
The results in Marvel’s Rivals were a bit different. FSR 4 only managed an average of 41 FPS, a notable drop from FSR 3.1’s 74 FPS. While the improved image quality was evident, especially in details like textures, the FPS loss was hard to justify in a fast-paced eSports title like this one. FSR 4’s benefits were less pronounced in games requiring quicker responses and higher frame rates.
It’s also worth noting that FSR 4’s performance gains diminish at lower resolutions like 1080p, where RDNA 3’s architecture struggles to push high frame rates with FSR 4. Overall, while FSR 4 offers excellent image quality and can enhance FPS in certain situations, it may not always be the best option for every gamer, especially when it comes to fast-paced titles or lower resolution settings.