AMD FSR is quickly getting unofficial implementations in several games, mods, and hacks. After mods that added FidelityFX Super Resolution to Grand Theft Auto V and Assetto Corsa, Georg ‘DadSchoorse’ Lehmann found a way to apply FSR to almost all Vulkan games on Linux as part of a full-screen Proton hack.
AMD’s FSR implementation in fshack allows users to select it instead of linear filtering for upscaling. It can be enabled using WINE_FULLSCREEN_FSR = 1 and a lower game resolution than the display’s native resolution. WINE_FULLSCREEN_FSR_STRENGTH controls the degree of sharpness (not to be confused with AMD quality presets, this concerns input resolution), 0 is maximum sharpness, higher values mean less sharpness. The default is 5.
YouTube user GloriousEggroll posted a video demo of this FSR hack used with Forza Horizon 4. According to GloriousEggroll, FSR Ultra Quality could squeeze an additional 25 frames per second when played back at 4K resolution and Ultra settings.