FSR 4 Upscaling Now Possible on Older GPUs

FSR 4 upscaling now runs on older GPU architectures providing improved performance and visual quality across multiple titles.

Hardware by Tanvir Kabbo on Sep 26, 2025

It is now possible to run FSR 4, AMD's next-generation machine learning-based upscaler, on older GPU architectures, including those from Nvidia. A recent leak of AMD source code revealed the ability to compile a DLL for FSR 4 that runs on older hardware.

This works by utilizing INT8 machine learning instructions, supported on RDNA 2 and newer, as well as Nvidia GPUs. Implementing FSR 4 on these older GPUs is straightforward for native FSR 4 games: you simply copy a few DLLs, rename them, and the upscaler is ready to use.

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Performance Testing and Benchmarks

We conducted initial testing using a 7700XT 12GB VRAM card to gauge performance, as concerns existed that INT8 FSR 4 could incur significant performance penalties. In Cyberpunk 2077 at 1800p with high settings and no ray tracing, native gameplay averaged 57.95fps.

XeSS 2.0 provided a 27.6% performance improvement over native. Injected FSR 4 delivered 34% faster performance, while FSR3 was still slightly faster, offering a 44% improvement over native, giving FSR4 roughly 92% of FSR 3 performance.

While questions remain about why this version exists in leaked form and why it was never officially released, it is clear that AMD may have prioritized FSR 4 for newer architectures first. The potential for INT8 FSR 4 is high, particularly for the upcoming next-generation PSSR on consoles.

Comparing FSR 4 Across Different Titles

In Monster Hunter Wilds on the 7700XT at 1440p with high settings and ray tracing enabled, native performance averaged 53fps. XCSS boosted performance by 24%, while the injected FSR 4 method increased it by 21.5%.

FSR 3 outperformed FSR 4 in this regard as well, showing a 37.7% improvement. Balanced upscaling modes showed FSR 3 to be approximately 13.3% faster than FSR 4, meaning FSR 4 operated at about 86.7% of FSR 3's performance. Despite this, the image quality improvements still make FSR 4 a worthwhile investment.

In Spider-Man: Miles Morales at 4K with optimized ray tracing, native performance was 44.89 fps. XSS made things 48% faster, FSR 4 made things 55% faster, and FSR 3 and ITGI practically doubled performance. This means that there could be issues or improvements in the game engine itself.

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Performance Considerations and Console Implications

Changing from FP8-based FSR 4 to INT8 impacts how the system works. It remains uncertain whether this leaked version matches AMD's official FSR 4 in terms of quality, but preliminary image comparisons suggest improvements over FSR 3.

However, as load increases or different content is processed, performance and image quality may diverge.

INT8-based upscaling might work for higher-end consoles like the PlayStation 5 Pro, but it's less likely to work for current-generation consoles because they don't have as much machine learning acceleration power. Getting the same level of quality and performance across different games as FSR 2 or FSR 3 is still hard.

Practical Use on PCs

We retested FSR 4 injection on the RX 7700 XT at 1440p, adjusting performance and ray tracing settings to approximate the PlayStation 5 performance mode. The upscaler maintained acceptable visual quality even at internal 720p resolution.

While shimmering effects on reflections highlighted areas that needed refinement, the overall output remained visually appealing.

FSR 4 backporting could especially benefit handheld devices, which are unlikely to feature RDNA 4 GPUs. Tools like OptiScaler even allow users to inject the leaked FSR 4 DLL into FSR 3.1 games without native FSR 4 support, providing a simple method for accessing a machine learning-based upscaler on older hardware.

FSR 4, Upscaling Now Possible, Older GPUs, NoobFeed

Final Thoughts

The leak gives us a one-of-a-kind chance to test and rate FSR 4 on older GPUs. There may be some performance trade-offs, especially at lower resolutions or with heavier workloads, but the quality enhancements and flexibility it gives are quite important.

If AMD officially enables FSR 4 backporting, handhelds and older RDNA 3 GPUs are likely to get a big boost in upscaling technology. This will provide gamers better graphics without having to buy new hardware.

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Tanvir Kabbo

Senior Editor, NoobFeed

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