I haven't had any lag issues with it and my HTPC is running a 12-year-old processor with a 10-year-old AMD GPU. Maybe it's an Intel or Nvidia driver issue? I'

I haven't had any lag issues with it and my HTPC is running a 12-year-old processor with a 10-year-old AMD GPU. Maybe it's an Intel or Nvidia driver issue? I'm running KDE and have it configured to disable the compositor when an app goes full screen. Maybe that's your issue? Try turning off desktop effects and screwing around with your compositor settings. Edit: I want to point out that since my GPU can't handle 4k the desktop resolution is limited to ~2k (whatever the highest was that it can handle at 60Hz--I forget now haha).