Overview: FSR 4 lands on older GPUs through community hacks
AMD’s FidelityFX Super Resolution 4 (FSR 4) has sparked interest beyond officially supported hardware after an accidental source code release. Modders quickly created DLL injections to enable FSR 4 on RDNA 2 (Radeon 6000 series) and RDNA 3 (Radeon 7000 series) GPUs, including various APU and handheld configurations. While the move isn’t sanctioned by AMD, it has opened a conversation about whether newer upscaling tech can be retrofitted to older architectures without native support.
What ComputerBase found: image quality vs. cost in performance
A German tech site, ComputerBase, conducted an in-depth round of tests to answer a practical question: is FSR 4 worth enabling on older, unsupported graphics cards? The verdict is nuanced. In their tests, FSR 4 delivered sharper, more detailed images than FSR 3.1 in many scenarios, signaling a meaningful quality upgrade. However, the gains come with trade-offs, including stability concerns and some artefacts in moving scenes. While the comparison videos show the improvements, they also highlight that the higher-quality mode isn’t flawless across every game or scene.
Under the hood: how FSR 4 performs on non-native hardware
Importantly, ComputerBase used the Int8-based approach rather than FP8 hardware acceleration. This choice affects performance and image quality dynamics. The results indicate that even without official FP8 support, FSR 4 can outperform FSR 3.1 on older RDNA cards, but it isn’t a perfect substitute for a native RDNA 4 FP8 path. In particular, vegetation detail and fine structures showed instability in some cases, while motion could reveal more noticeable artefacts. The takeaway is clear: FSR 4 on unsupported GPUs can be a noticeable upgrade, but not a flawless one.
Compatibility and the reality of hacks
The testing also underscored reliability issues. While 14 of 18 tested titles ran FSR 4, some games demanded alternate hack methods to avoid crashes, and others failed entirely due to anti-cheat interactions or other protection schemes. In practice, your mileage will vary by title and the specific software environment. The modular nature of the hack means it’s not a one-click solution, and users must be prepared to tinker with game files or system configurations to achieve a working setup.
Performance cost: quantify the FPS impact
When it comes to frame rates, the numbers are tangible. Compared with FSR 3.1, ComputerBase measured a dip of roughly 9% to 12% in FPS using Performance mode on the RX 7800 XT, and about 10% to 13% on the older RX 6800 XT. By contrast, the officially supported RX 9060 XT—with FP8 hardware acceleration—saw only a 3% to 5% FPS drop in the same mode. That gap highlights the practical trade-off: the unofficial FSR 4 path costs more GPU cycles and memory bandwidth while delivering clearer visuals.
RDNA 2 vs RDNA 3: who benefits more?
Interestingly, the results did not show a straightforward edge for RDNA 3. In some tests, RDNA 2 performed on par with RDNA 3, suggesting that the expected WMMA Int8 accelerations may not be fully realized on all implementations. This finding implies that, when using community-driven FSR 4, the architecture-specific gains may be more dependent on individual game workloads and driver quirks than on the GPU generation alone.
Bottom line: is it worth it on older hardware?
For enthusiasts who enjoy tinkering and want to squeeze extra image clarity from unsupported GPUs, FSR 4 offers a meaningful boost over its predecessor and can be worth trying. It’s not a guaranteed upgrade—expect variability by game, potential instability, and a non-trivial setup process. Those seeking a straightforward, officially supported improvement should wait for a sanctioned implementation or upgrade hardware to a version with FP8/official support. Until then, the community hack stands as a testament to what fans will do to push visuals further, even if the road is a bit bumpy.
Practical tips if you decide to experiment
- Backup game files and be prepared to revert changes if crashes occur.
- Test a few titles first to gauge stability and the perceived quality gains.
- Monitor for artefacts in motion and adjust settings accordingly.
- Keep expectations in check: the improvement is real, but not identical to native FP8-based FSR 4 on supported hardware.
Overall, this unofficial FSR 4 path reaffirms AMD’s upscaling potential while highlighting the cost of compatibility, stability, and real-world performance. It’s a clever workaround rather than a replacement for official support, and it’s likely to fuel ongoing discussions about when and how game developers and AMD will deliver proper, guaranteed FSR 4 on older RDNA generations.
