AMD FSR Redstone in detail – milestone and real counterpoint to NVIDIA’s DLSS?

1 - Introduction, three looks back and one forward 2 - ML Radiance Caching in Detail 3 - ML Ray Regeneration in Detail 4 - ML Upscaling in Detail 5 - ML Frame Generation in Detail 6 - Aktiviation of FSR4 in game or in the Adrenaline drivers 7 - Benchmarks and Metrics 8 - Quality Comparison and Conclusion

Requirements for FSR4 in terms of hardware and software

FSR4 provides fully ML-based components for the first time and therefore requires a clearly defined technical basis. On the hardware side, a current Radeon GPU with dedicated AI accelerators and sufficient inference performance is required. Earlier Radeon generations and all competing GPUs do not offer these functional units, which is why the Redstone components cannot be activated there. This clearly distinguishes FSR4 from previous FSR versions, which were traditionally very broadly compatible and also supported older systems.

On the software side, the respective game must implement the complete Redstone pipeline. In addition to the low-rendered input frame, this also includes motion vectors, depth buffers, color information and other G-buffer structures. In order to use ray regeneration, complete ray tracing data channels are also required so that the ML model receives a stable input signal. FSR4 cannot be initialized without these structural requirements. The function also requires a current Radeon graphics driver that provides the redstone runtime components and controls the engine accordingly.

Only when all conditions are met does the game recognize the complete ML render path and can integrate FSR4 technically correctly. This makes FSR4 less of a drop-in solution like previous FSR versions and more of a stand-alone rendering component that needs to be tightly integrated into the engine.

Activation of FSR4 within a supported game

If all technical requirements are met, FSR4 can be activated directly via the game’s graphics menu. The process begins with the selection of the upscaling method, whereby the game explicitly offers FSR Redstone if Redstone integration is available. After the selection, the familiar quality levels are available, which determine the internal render resolution. Balanced mode generally provides the best compromise between image quality and performance, while Performance and Ultra-Performance are designed more for maximum frame rate.

If Frame Generation is supported, the corresponding option only appears after selecting FSR4. The game must provide precise motion vectors for this, as the ML model derives synthetic intermediate frames from successive images. Activation is independent of the upscaling mode, but requires that the title has worked cleanly temporally and that there are no hidden restrictions in the simulation clocks or the camera and object movement. For raytracing-heavy titles, the option for ray regeneration is also available, provided the engine generates the necessary raytracing buffers. Why FSR 3.1 is still displayed here is explained in the next chapter.

The entire activation process thus remains internal to the game and follows a clear sequence that does not differ from the previous FSR workflow, but unlocks additional options as soon as the ML components are provided. FSR4 deliberately acts as a coherent render pipeline that fully refines and stabilizes the image through ML processes before it is output.

Activation of FSR4 via the driver in games with existing FSR 3.1 integration

For games that already support FSR 3.1, the Radeon driver provides a way to prioritize FSR4 if the game correctly generates the necessary technical base buffers. In these cases, the driver can predefine that the ML upscaler is automatically used for recognized redstone structures. However, this only works if the engine already provides complete motion vectors, depth buffers and color channels in accordance with the FSR 3.1 specification. If individual components are missing or the quality of the temporal data is insufficient, the driver does not intervene and leaves the game in FSR 3.1 mode.

Activation takes place via the global graphics options of the Radeon software. There, FSR4 can be defined as the preferred upscaling path, whereby compatible games automatically request the ML variants. Frame Generation follows the same principle, but also requires a complete temporal data structure of the game. The game itself ultimately decides whether it can use FSR4. The driver does not replace missing data buffers, reconstruct motion vectors or extend incomplete render graphs.

This is also the necessary brake on euphoria: not every FSR 3.1 game automatically becomes an FSR4 title. Practical activatability depends strictly on the quality of the existing engine integration. Games with incomplete G-buffer structures, imprecise motion vectors or proprietary temporal paths cannot use FSR4, even if they have been activated in the driver. In such cases, FSR 3.1 remains the functionally correct and more stable mode.

This creates an orderly transition where FSR4 is automatically used in new or updated titles, while older games continue to use their proven FSR 3.1 implementation. This prevents malfunctions and ensures that ML upscaling and frame generation are only used if the underlying data structures technically allow it.