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.
Maybe it’s not the CPU but with FSR either way the real frame rate drops which is why you get input lag. The game logic/game loop is only calculated per real frame. Which means if you take a 20% drop in real frame rate you are going to get 20% more input lag.
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.
And in that case, frame generation will cause even more input lag I guess. I’m thinking frame generation is best for systems where the GPU is the bottle neck, I guess, input lag wise? Where it gets served frames ASAP, and can interpolate frames as soon as the latest, and second latest frames are available. Which it does anyway, but it has to wait less, then.
If you get higher real FPS via upscaling, a lower resolution. It can improve input latency and sim speed.