[sph]

> go ahead and play a 4k clip on Wayland enabled Firefox then move the mouse pointer, it stutters like crazy.

Either your DE or your Firefox aren't actually using Wayland because for me it's incredibly smooth, and CPU usage is in the low 10%. Fedora 35 on a 6800 XT here.

Firefox still needs tweaks to have actual complete hardware video acceleration.

[ttarr]

I should've been more clear, Firefox is just an example, my problem is the mouse pointer being affected by heavy load of any kind on the GPU/UI thread.

As coldblues said, it's probably Mutter not having an independent thread for the mouse pointer, X11's pointer handling is independent from Mutter/KWin it seems.

See the demo here to know exactly what I'm talking about: https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1241

[quotemstr]

> the mouse pointer being affected by heavy load of any kind on the GPU/UI thread.

It's because of stuff like this that we should treat UIs more like real time systems. There's really no good reason at all that a modern machine can't render every frame perfectly every time regardless of system load --- it's due to inadequate attention paid to isolating real-time-ish paths like mouse cursor movement, composition, input event dispatch, and so on from app-induced loads that we get weird responsiveness issues. X actually did a better job in this particular respect than your typical Wayland compositor --- it used interrupt driven mouse cursor rendering, for example.

[sph]

Weird, I'm not seeing it, not even with a GPU heavy game being rendered in a window.