I have a few dodgy cheap SSDs, so I’m not surprised by slow I/O performance in general. But my Plasma desktop frequently freezes for 1-3 seconds (including the cursor!) whenever there is high IO load, for example while installing a Steam game.
Updating the screen should be completely independent from I/O, shouldn’t it? Is there anything I could’ve misconfigured in my Arch Linux? I’m running Plasma 6.1.4 in Wayland.
Years ago I had a similar problem that was resolved by changing the method of I/O scheduling.
https://www.techrepublic.com/article/how-to-change-the-linux-io-scheduler-to-fit-your-needs/
I’m not sure which one I used or if this is still relevant with modern Linux but it’s something to look into that might help.