SUMMARY The mouse speed on kwin when scale is enabled doesn't match the speed on other systems. For example, if I uses 1920x1080 system, when I set the scale, the mouse (physical one, not touchpad) feels moves much faster. And it is significantly faster comparing to other OS (e.g. windows) or X11 on the same machine. I have to use the mouse hardware dpi button to adjust back and force when switching the system to get the same speed feeling. On other OS or X11, no matter how the scale is changed, I don't feel the mouse speed is changed at the same time. STEPS TO REPRODUCE 1. Set scale to >100 (e.g. 125) 2. Move mouse OBSERVED RESULT Mouse is significantly move faster on scaled screen EXPECTED RESULT Mouse moves the same speed before the scale is enabled. SOFTWARE/OS VERSIONS Linux/KDE Plasma: KDE Plasma Version: 6.1.5 KDE Frameworks Version: 6.6.0 Qt Version: 6.7.2 ADDITIONAL INFORMATION
This is intentional, mouse speed is relative to the size of content and not to the resolution of the screen. If you want to make the cursor slower, you can use the mouse settings to reduce its speed.