uses the hardware-accelerated feature of the AMD RDNA™ 4 architecture
AMD FidelityFX™ Super Resolution 4 upscaling requires an AMD Radeon RX 9000 Series GPU or better and can only be used on appropriate hardware.
Requirements
[FSR 4 Upscaling] AMD Radeon™ RX 9000 Series and above
It’s possible they add compatibility at a later time (with reduced performance and/or quality due to lack of hardware acceleration), but they haven’t announced anything like that currently
Source on RDNA3 on Linux not doing FSR4? Linux drivers are far ahead of Windows drivers.
Source is RDNA3 not being able to handle FP8 on any OS. It just can’t do FSR4.
There is an unofficial INT8 version of FSR4 that was leaked from AMD that works on RDNA3, but it’s a lot slower, and FSR4 is already pretty heavy.
Would FP8 be exposed as the VK_KHR_shader_float8 vulkan extension?
https://gpuopen.com/fidelityfx-super-resolution-4/
It’s possible they add compatibility at a later time (with reduced performance and/or quality due to lack of hardware acceleration), but they haven’t announced anything like that currently
It’s not a hard requirement. Gamers have used the SDK to get FSR4 working on Steam Deck. Here’s a video of it in action.
https://www.youtube.com/watch?v=95N6-2U5YQo
TL;DW – It’s good to have as an option but not necessarily better than FSR3 on Deck due to tradeoffs. Depends on the game.