SUMMARY Dolphin uses an extraordinary amount of CPU for the selection rectangle. This dramatically worsens as resolution increases. As a result, it feels quite choppy. It's especially noticeable on high refresh monitors. I'm guessing something accidentally hit O(n^2) instead of O(n). STEPS TO REPRODUCE 1. Open Dolphin, maximized. On a high res screen if possible, or alternatively at low display scale factors 2. Watch CPU usage for Dolphin, in my case I just ran htop --pid=$(pgrep dolphin) --delay=1 3. Click and drag anywhere in the window (and not by scrolling, but by moving the mouse cursor) OBSERVED RESULT Dolphin's CPU usage spikes to the point it maxes out a core and the effect feels really choppy EXPECTED RESULT Select dragging is performant, not choppy, and doesn't max out a core SOFTWARE/OS VERSIONS Linux Version: 6.5.3-arch1-1 KDE Plasma Version: 5.27.8 KDE Frameworks Version: 5.110.0 Qt Version: 5.15.10 KWin Backend: Wayland Mesa 23.1.7 (AMD RX 6600 XT) ADDITIONAL INFORMATION Note this is NOT to do with selecting files/folders and moving them. This is only as you CREATE the selection box.