Last month, AMD accidentally made FSR 4 open-source by publishing the entire source code on GitHub, as part of its FidelitySDK. That pushed modders to quickly reverse-engineer how to run FSR 4 on previously incompatible hardware, but the hacks were limited to Linux. As such, they saw only 100-107 FPS in Stellar Blade when using FSR 4, compared to 110+ FPS on FSR 3. Rather, they pitted an RX 7900 XTX against an RX 9070 XT — AMD's latest flagship purpose-built with FSR 4 in mind. In Cyberpunk 2077, tested at 4K Ultra settings, the 9070 XT netted 77 FPS using FSR 3.1 and only 74 FPS using FSR 4.