I was trying out FSR4 on my RX 6800 XT, Fedora 42. Works really well and it easily beats FSR3 in visuals even on Performance. It does have a significant performance hit vs FSR3 though but it still works out to be a bit faster than a native rendering on Quality.
Isn’t FSR supposed to give better performance/real fps?
It is (if we talk about FSR as upscaler tech). But it wont help in CPU bound scenarios where the GPU already has to wait for CPU.