New benchmarks have revealed that while AMD’s FidelityFX Super Resolution 4 (FSR 4) can technically run on older RDNA 2 and RDNA 3 graphics cards, the performance hit compared to FSR 3.1 is significant — especially when using the unofficial INT8 variant of the upscaler.
FSR 4 on RDNA 3 and RDNA 2: Unofficial but Functional
Officially, AMD’s FSR 4 only supports RDNA 4 (Radeon RX 9000 series) GPUs, which natively handle the FP8 data format used in the new upscaling model. However, thanks to leaked INT8 model files, users have managed to get unofficial FSR 4 INT8 builds running on RDNA 3 and RDNA 2 GPUs.
According to ComputerBase’s testing, this workaround does deliver the improved image quality of FSR 4, but it comes at a noticeable performance cost.
Benchmark Results: RX 7800 XT and RX 6800 XT vs. RX 9060 XT
In Quality Mode at 1440p resolution, both the Radeon RX 7800 XT and RX 6800 XT showed 9–13% lower performance with FSR 4 INT8 compared to FSR 3.1.
| GPU | FSR Version | Average FPS (1440p Quality Mode) | % Difference |
|---|---|---|---|
| RX 9060 XT (RDNA 4) | FSR 4 FP8 | ~–3% vs FSR 3.1 | Minimal loss |
| RX 7800 XT (RDNA 3) | FSR 4 INT8 | –9% vs FSR 3.1 | Noticeable |
| RX 6800 XT (RDNA 2) | FSR 4 INT8 | –10% vs FSR 3.1 | Noticeable |
On the Performance Mode, both older GPUs managed to recover some ground — even outperforming FSR 3.1 slightly — but the frame rate still lagged behind RDNA 4 results by around 12–13%.
Visual quality, however, saw clear gains. While FSR 4 FP8 remains superior overall, ComputerBase noted that FSR 4 INT8 still offers sharper detail and cleaner motion compared to FSR 3.1, though the difference varies by game and scene.
What This Means for Gamers
The findings confirm what many suspected: FSR 4’s advanced AI upscaling pipeline heavily depends on the FP8 instruction set, limiting full efficiency to RDNA 4 GPUs. While the INT8 workaround enables older GPUs to experience FSR 4’s improved visuals, users should expect a 10–15% performance penalty on average.
AMD has not yet confirmed whether it plans to release an official INT8 build of FSR 4 for RDNA 2 or RDNA 3 GPUs. However, given the community interest and the relative stability of unofficial tests, many players are hoping AMD will make the support official in a future driver update.
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