Gamers and modders are utilizing AMD files, which were accidentally leaked, to enable FidelityFX Super Resolution (FSR) 4 on older hardware. The experiments have successfully made the latest upscaling technology functional on RDNA 2 graphics cards from the RX 6000 generation, a series for which it was not designed. While this unofficial implementation results in a performance decrease on the older cards, it offers a notable improvement in image quality.
AMD’s FSR4 is the company’s newest dynamic, AI-powered upscaling model. Previous generations of FSR were known for their broad compatibility across AMD, Nvidia, and Intel GPUs. In contrast, FSR4 is designed to be exclusive to AMD’s latest RDNA 4 GPUs in the upcoming RX 9000 series. This includes GPUs such as the RX 9060 XT, even though higher-end last-generation cards like the RX 7900 XT and RX 7900 XTX remain powerful options for raw rasterization.
Following the file leak, modders have tested the technology on various hardware. According to ComputerBase, FSR4 runs well on RX 7000 series cards, with better performance on more powerful models. For the older RDNA 2 architecture, VideoCardz reported a modder running FSR4 on an RX 6800 XT in the game Stellar Blade. The test showed a performance drop of approximately 10-20%. However, the visual output was described as “much prettier” than other upscaling models like XeSS. The modders suggested the trade-off is worthwhile primarily in games that already achieve frame rates around 100fps.
The performance decrease on older cards is due to the absence of Wavefront Matrix Multiple Accumulation (WMMA) accelerators. These hardware components are only present on AMD’s new RX 9000 GPUs. On supported hardware with WMMA, FSR4 is expected to cause only a minor performance hit of a few percent. To get the modification working, users had to run an older AMD Radeon driver, version 23.9.1. The mod is confirmed to function on both Linux and Windows operating systems.
The exclusivity of FSR4 marks a shift from AMD’s previous open-source approach to its upscaling technology. There is discussion about whether AMD will make this expanded compatibility official. Some reports mention a potential future Redstone driver update that could broaden support, especially since unofficial mods have demonstrated that the technology can function on older hardware.
