Created attachment 105990 [details] qdbus org.kde.KWin /KWin supportInformation Discussed here too - https://www.reddit.com/r/kde/comments/6fznb3/plasma_desktop_not_rendering_in_144fps/ I have 2 monitors, both are 1920x1080, one of them is 144Hz, one 60Hz. In Plasma, both monitors are rendering in 60Hz. When I launch a game like Dota 2 and move windows around on top of the game, they're rendered in 144Hz. I worked around this by adding [Compositing] MaxFPS=144.0 To kwinrc.
Created attachment 105991 [details] xrandr -q
Created attachment 105992 [details] pacman -Q (list of all installed packages)
A system with two different refresh rates cannot be properly supported on X11. The compositor uses one window and that gets rendered to both screens. It is quite likely that the X server restricts the refresh rate to the least common denominator, which would make sense. As there is a workaround by forcing the FPS, this looks fine to me.