I see the same on Kubuntu 16.04 LTS. Removing all animated(!) icons from the systray made the issue disappear. I got the idea from this: https://bugs.kde.org/show_bug.cgi?id=356479
** Bug watch added: KDE Bug Tracking System #356479 https://bugs.kde.org/show_bug.cgi?id=356479 -- You received this bug notification because you are a member of Kubuntu Bugs, which is subscribed to plasma-workspace in Ubuntu. https://bugs.launchpad.net/bugs/1597792 Title: plasmashell high CPU usage (100%+) To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/plasma-workspace/+bug/1597792/+subscriptions -- kubuntu-bugs mailing list kubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/kubuntu-bugs
