Modder injects AMD FSR 3.1 upscaling into Xenoblade Chronicles 2 on Switch

A GBAtemp developer's new plugin, xc2fsr, adds AMD FSR 3.1 upscaling and frame generation to Xenoblade Chronicles 2 on a modded, overclocked Switch.

AI-drafted from 1 source. This story was written with AI from the outside reporting listed under Sources, and checked by automated tools before it went up. The originals have the full detail.

A modder has built a plugin that injects AMD's FSR 3.1 upscaler into Xenoblade Chronicles 2, running on a Nintendo Switch. The tool, called xc2fsr, replaces the game's native anti-aliasing pass in docked mode with FSR upscaling and adds optional frame generation, pushing the game towards a true 1080p image and, in some modes, 120 frames per second.

The plugin comes from GBAtemp developer masagrator, who describes themselves as working on Switch performance patches, and was posted to the GBAtemp thread on 18 October. It targets game version 3.0.1 and has, according to the thread, been tested on a 4GB Switch, the memory configuration used in the original 2017 console.

What FSR 3.1 actually replaces

Xenoblade Chronicles 2 normally renders at a dynamic resolution and leans on TMAA, a temporal anti-aliasing technique, to reconstruct a 1080p picture in docked mode. masagrator's writeup says xc2fsr swaps that TMAA output for FSR 3.1, AMD's open upscaling technology, while rendering the 3D scene at a maximum of 728p and keeping the UI at native 1080p. The developer describes the shaders as “heavily optimised” for the Switch's hardware, deliberately avoiding scratch memory and excess register use so the technique fits inside a console with far less GPU power than the PC and console hardware FSR usually targets.

Frame generation, which interpolates extra frames between ones the game actually renders, is also included, with multipliers up to 4x aimed mainly at cutscenes rather than gameplay, since the UI is not generated and can look choppy if pushed that far. The debug menu, opened with ZL and D-pad down according to the thread, exposes a long list of toggles: anti-aliasing mode, sharpening strength, bloom quality, dynamic resolution bounds for both docked and handheld play, and a statistics overlay showing frame times for both FSR and frame generation.

The clock speeds and the caveats

To hit a steady 30 frames per second at 1080p with FSR and the default dynamic resolution setting, the thread lists clock speeds of at least 1020MHz CPU, 1075MHz GPU and 2131MHz RAM, speeds above the Switch's stock docked profile. masagrator says testing has so far only covered the game up to the start of Chapter 2, and lists several bugs that needed separate fixes once the frame rate rose past 30fps, including weather effects, particle timing, quick time events, camera rotation speed and quest title animations.

The thread also flags a compatibility check: if another existing patch, FPSLocker, is detected, the on-screen plugin indicator turns red and xc2fsr will not run alongside it. Running the 1080p mode with 4x frame generation can add more than 100MB to the game's memory footprint, enough, masagrator warns, to crash the game if something else, such as forced video capture, is also using RAM.

What is next, and what is not being shared

masagrator says a version for Xenoblade Chronicles: Definitive Edition is planned for the following week, with Xenoblade Chronicles 3 support to follow once a Switch 2 update for that game ships, so the offsets used to hook the engine do not need reworking twice. Source code is being withheld for now, with the developer writing that releasing it before an XC3 version exists risks “ai slop kids releasing it for XC3” first. masagrator also discloses that “main work was made by Claude,” the AI model, working from the developer's own knowledge of the game's internals, an unusually direct admission of AI assisted modding on a thread otherwise full of register level shader detail.

What is not yet clear is how the plugin behaves beyond the tested early chapters, how it holds up in handheld mode, which the thread says is cropped to 720p rather than upscaled, and whether the required overclock sits within margins most Switch units can sustain for long sessions. None of that has been verified outside the thread itself.

Sources

Image: GBAtemp.net - The Independent Video Game Community

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