THE CRUNCH
The OptiScaler community project, which aims to make upscaling and frame generation work across GPU brands, has modded AMD FSR 4.1.2 to run on Intel Arc graphics cards using Intel's XMX cores (Xe Math Extensions). Until now, FSR on Arc relied on a fallback DP4a path that offers a significantly lower performance benefit. Reddit user DarkerThanLpDark tested FSR 4.1.2 Lite on an Arc B580 in "Clair Obscur: Expedition 33," comparing it with the game's native XeSS implementation and FSR's standard DP4a implementation on Arc. The mod came out almost level with XeSS (SR): FSR 4.1.2 Lite logged an upscaling time of 0.59 ms against 0.58 ms for XeSS (SR).
That gap of one hundredth of a millisecond matters because the current DP4a route is the reason FSR has lagged on Arc: it is a fallback that delivers a significantly lower performance benefit than the machine-learning path the mod unlocks. With XMX cores doing the maths, FSR 4.1.2 effectively performs on par with the upscaler Intel built for its own hardware.