AMD FSR 4 Running On Radeon RX 6800 XT Gives Image Quality A Boost But At A Big Cost

Since the AMD FSR 4 INT8 DLL leak, we've known that it's possible to use FSR 4 on older GPU architectures than RDNA 4. Recently, we've actually seen successful use of FSR 4 on AMD's RDNA 2 architecture, after early efforts resulted in bugged visuals. Per a Reddit guide posted yesterday by user u/NaM_777, users of AMD RDNA 2 GPUs like the RX 6950 XT or 6800 XT will need to use the AMD Radeon 23.9.1 driver and not update they want to use FSR 4 in their games. This means that not only will AMD FSR 3 perform worse than FSR 2 or other upscalers on those GPUs, but performance updates, bug fixes and new features from the driver updates in the two years since won't be available to those users.

While these are indeed major downsides, the results with AMD FSR 4 on the RDNA 2 architecture do look quite good, as highlighted by the screenshot of Stellar Blade originally posted to Chiphell forums below. The same Chiphell user reported that Stellar Blade dropped to an average of 100-107 FPS after enabling FSR 4 Quality compared to an average 110 FPS with FSR 3 Quality, which makes for an up-to-20% reduction in performance from FSR 3 on the older RDNA 2 architecture. On RDNA 3 cards using this trick, the performance drop was more like 6% when tested in Cyberpunk 2077, and didn't require a driver regression to perform adequately.


In any case, it's interesting to see older GPUs like the RX 6800 XT and RX 6950 XT get a new lease on life through sufficiently-determined community members. In the case of using the OptiScaler FSR 4 method on older GPUs, though, we find it hard to recommend the move for users who aren't on at least RDNA 3 cards. Needing to use two year-old drivers is a fairly severe downside sure to impact baseline performance and compatibility with several games, and the tradeoff of cleaner upscaling won't be worth it in scenarios where a game gets broken or loses too much base performance. Hopefully, though, these advances mean that AMD will find an official way to support FSR 4 on older GPUs via the INT8 model, since it clearly is still possible.

Image Credit: Chiphell (via WCCFTech), Shift Up Corporation