In December, AMD unveiled the Redstone technology package, which builds on the AI-based FSR4 upscaling introduced with the Radeon RX 9000 series. Redstone added AI-based frame generation, Neural Radiance Caching, and Ray Regeneration. The upscaling component itself, however, was not updated to a new version. It seems that’s changing now with the FSR 4.1 update, which will apparently arrive in one of the upcoming driver releases.
AMD has not yet officially announced this update, but it has quietly surfaced in public. A library file (amdxcffx64.dll) implementing FSR 4.1 has appeared, apparently originating from upcoming Radeon graphics drivers. The file is believed to come from a build that is currently undergoing closed beta testing as part of the “Vanguard” program. It reportedly comes from drivers with version number 26.3.1.
You may recognize the file name if you use the Optiscaler software to “hack” upscaling into games that, for example, lack FSR support but support DLSS 2 or XeSS. This is precisely the library you replace when trying to enable FSR4 in a game that does not yet officially support it and where automatic upgrading from FSR 3.1 does not work either. Some users have already tested the leaked library in this way and confirmed that it appears to be genuine (at least it seems to be signed by AMD), there are example screenshot comparisons here and here.
According to this limited testing, the new FSR 4.1 version appears to introduce changes in image quality, while performance should remain the same. Compared to the original FSR4, the new version reportedly appears to improve vegetation rendering in Hogwarts Legacy, which was one of the game the leaked file was tested in. Hopefully this will be confirmed and the update will indeed deliver better visual quality.
Still RDNA 4 only
However, the leaked FSR 4.1 file still requires support for FP8 value computations, which means it does not differ from the originally released FSR4 in this regard. Nothing therefore appears to change concerning hardware requirements—this new version of the technology will likely work only on Radeon RX 9000 graphics cards with the RDNA 4 architecture (and possibly RDNA 4m in future integrated graphics).
On the other hand, this does not completely rule out the possibility that AMD could separatelyrelease something like an FSR4 “Lite”, which would use INT8 instructions and—at the cost of lower image quality—work on RDNA 3 or perhaps even RDNA 2 GPUs. Such a technology would most likely be implemented in a separate library and therefore would not necessarily be present in the standard FSR 4.1 library—which could explain why it is not included in the currently leaked file. As for the likelihood that such a compatible version of FSR4 will still be released, that remains unclear at best. It’s probably safer to be sceptical about it.
Coming in March?
The driver version number from which the leaked library reportedly originates (26.3.1) would imply that this driver—and the FSR 4.1 with it—could be released sometime this month. That’s something that is possible, but not guaranteed. In theory, AMD could decide to postpone the release of this feature and “unlock” it only in a later driver version rather than in the final public release of driver version 26.3.1, after the testing is over…
Sources: VideoCardz, Reddit, Guru3D
English translation and edit by Jozef Dudáš
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