Implementation-ready Software Development Kit for FSR Redstone now available
AMD has released FSR SDK 2.1.0, the first public package that lines up with its “Redstone” branding. The update is now live on GPUOpen and GitHub for developers targeting DirectX 12 on Windows 10 and 11.
The SDK bundles all four ML-based FSR features: FSR Upscaling 4.0.3, Frame Generation 4.0, Ray Regeneration 1.0, and Radiance Caching as a preview. AMD’s own notes classify FSR Upscaling 4.0.3 as an updated effect, not a new one, which matches the shift from the old “FSR 4” label to the simpler “FSR Upscaling” name while the core tech keeps evolving. Frame Generation, Ray Regeneration and Radiance Caching are listed as new effects built around neural rendering.
Radiance Caching is still not a full release and is only offered as a preview DLL and sample code, so it will take time before it appears in shipping games.
Source: Github
FSR SDK 2.1 also formalizes the FSR API with a loader plus separate DLLs for each feature: amd_fidelityfx_loader plus upscaler, frame generation, denoiser, and radiance cache libraries. This structure allows future AMD Software: Adrenalin Edition drivers to update ML components on the driver side and even upgrade existing FSR 3.1 integrations in supported games to FSR Upscaling 4.0.3 and Frame Generation 4.0 without new game patches. An updated Unreal Engine plugin is part of the rollout.
Source: AMD
Hardware support remains limited to Radeon RX 9000 series and newer for the ML paths. Older Radeon GPUs and other vendors fall back to analytical FSR 3.1, so Redstone’s ML features are clearly pitched as a RDNA 4 feature set.
For game developers, SDK releases like this are what matter most because they define the actual APIs, integration path, and hardware matrix that ships in real games. AMD still offers samples and helper code under permissive terms, but the ML parts of Redstone come as pre-built, signed binaries with only limited source, so the core of FSR Upscaling 4, Frame Generation, Ray Regeneration, and Radiance Caching is not fully open source.
Source: FSR SDK (GPU Open/Github)
