I have disabled the notification widget within the tray area. I have done so because of this bug: https://bugreports.qt.io/browse/QTBUG-45959 which causes my CPU to go to 100% while there is a spinner being shown. I don't even have an nvidia card, they are approaching it wrong. But regardless of that, in the old days of KDE 4, disabling the notification applet would mean that rather than getting something as a notification while copying a file, I would get a window displaying the progress. One window per copy/move operation. And notifications would still appear, just in an uglier window. That is what I was hoping would happen when I disabled the notifications. What actually happened is that I had no way of knowing whether the file copy was complete or not. Could you please reimplement this missing feature? Or, if you think that the notifications are necessary, just remove the option to disable the plasmoid. Reproducible: Always
*** This bug has been marked as a duplicate of bug 356904 ***
Also, we have significantly improved this area in the latest KDE frameworks release. See if this fixes the high CPU usage for you.