Not just for the Steam Machine: Valve adds new AMD feature

As Reddit user u/Helpful-Assignment-6 discovered, Valve recently integrated a new AMD library into Steam. Specifically, the file is a DLL (Dynamic Link Library) that some users believe could eventually be distributed through Proton Experimental to let games with FSR3 support benefit from FSR4-related functionality. The file name, amdxcffx64.dll, points to AMD’s FidelityFX Super Resolution technology. However, there is currently no definitive proof that the library actually includes FSR4 features, and it may serve a different purpose entirely. Even so, the discovery has sparked plenty of speculation.

FSR renders a game at a lower internal resolution and then upscales the image. The goal is to increase frame rates while maintaining high image quality and reducing GPU load. If Valve makes FSR4 available directly through Proton, many Windows games running on SteamOS could benefit without requiring separate updates from their developers.

Such a feature could be especially useful for the upcoming Steam Machine. Valve’s living room gaming PC is unlikely to match the raw performance of a high-end gaming desktop, but FSR4 could help demanding games run at higher frame rates or with better graphics settings. Some fans also see the added AMD library as another hint that the Steam Machine’s launch may be approaching. Many are currently hoping for an announcement on June 23, 2026.

Not just relevant for the Steam Machine

The potential benefits would go beyond Valve’s living room PC. The Steam Deck, future SteamOS handhelds and compact gaming mini PCs could also benefit from tighter FSR integration. FSR4 was originally designed mainly for newer Radeon GPUs, leaving older RDNA2 and RDNA3 graphics cards with fewer advantages. If Valve provides the necessary AMD libraries centrally through Proton, SteamOS could automatically select the best available upscaling option based on the installed hardware. Newer Radeon GPUs could potentially use FSR4, while older graphics cards might still benefit from improved or adapted FSR features. For now, however, all of this remains speculation.