The animation done by the Notifications (32x32 pixel animation in systray) is making Xorg process take up a whole core of cpu power. Reproducible: Always Steps to Reproduce: 1.Take a look at Xorg cpu usage 2. start big file transfer that results in little spinning thing in systray 3. take a look at Xorg cpu usage Actual Results: Xorg uses all the CPU it can get its hands on. Expected Results: no measurable cpu impact Deactivating the notifications in the systray during the file transfer instantly reduce the Xorg usage to normal. This is probably a real killer for mono-core CPUs
trying to debug, I enabled kwin FPS and paint effects. When the notifications icons is spinning, my FPS(as repoted by KWin) falls from 60 to 25-30 It's only painting in the ca. 32x32 notifications spinning icon in systray
*** This bug has been marked as a duplicate of bug 311799 ***