AMD briefly made the source code for its new FidelityFX Super Resolution 4 (FSR 4) tech available online, drawing attention from many people. The files appeared on GitHub during the launch of FidelityFX SDK 2.0 but were quickly removed.
If you didn't know, FSR 4 is AMD’s latest upscaling technology that is designed to improve performance and visual quality in games. It builds on FSR 3.1 and introduces FP8 instruction-based processing, optimized for the new RDNA 4 GPU architecture.
The leaked code contained two variants. One used FP8 instructions for RDNA 4 GPUs, while another used INT8 instructions, hinting that AMD had tested compatibility with older RDNA 3 graphics cards. Of course, the community quickly noticed the files before they were taken down.
Officially, AMD recommends FSR 4 for the Radeon RX 9000 and above series of cards, emphasizing the FP8 path. However, the appearance of the INT8 variant in the leak suggests the company considered broader support, though no official statements have been made to confirm this possibility.
As for the FidelityFX SDK 2.0 release, it arrived alongside FSR 4 to provide developers with tools, signed binaries, and Unreal Engine 5 integration. It also brings stability improvements, reduced ghosting, and enhanced visual fidelity compared with previous FSR versions.
Earlier versions of FSR technology, including FSR 1 and 2, were made partially open source through AMD’s GPUOpen platform. This allowed developers to modify and integrate the technology freely under the provided licensing terms.
Given this accidental release, it is clear that AMD could easily make FSR 4 open source if they chose to. The leak demonstrates that the code is accessible and structured for developers. Will they decide to officially open source FSR 4? Only time will tell.
