But often noticeable only upon very detailed examination
The authors of the Hardware Unboxed channel compared Nvidia DLSS and AMD FSR scaling technologies in modern games and Full HD resolution, where upscalers perform worse than in higher resolutions.
Technologies were compared in games such as Cyberpunk 2077, Ratchet & Clank Rift Apart, Dead Space, Star Wars Jedi Survivor, Starfield and several others. But all the games were quite fresh.
The comparison showed that DLSS is still better than FSR. Not always and not everywhere. For example, in Cyberpunk 2077, the asphalt texture is much better rendered when FSR is activated, but then FSR shows a much more obvious ghosting effect. In general, when FSR is activated, various image artifacts appear more often and more strongly, including flickering, ghosting, ghosting, and so on. The authors of the video say that FSR lags significantly behind DLSS and native rendering in terms of image quality in most games tested. Let us repeat, the conclusion is valid specifically for Full HD resolution.
In fairness, it is worth saying that sometimes the very artifacts that the authors of the video talk about are not easy to detect on the video, even if the video is zoomed in and slowed down, and even after the author explains what exactly to look for attention. And during a dynamic game, without looking at the picture in this mode, many players do not notice any problems — many such comments can be found on various platforms in relevant topics.