compatico wrote: I won't be upgrading to v17.x or v18.x until the mouse issue is fixed either - I have a multi-monitor setup and the horribly slow mouse makes the desktop unusable, even with tools to increase mouse speed, it's still too slow.

Just ran a live Kubuntu v18.04 beta and mouse speed/acceleration issue is still present. I need a fast mouse to navigate across my monitors and this is just useless as is. I'm using a standard wheel mouse on USB...it can't be that hard to fix.

I found a simple solution:
Turn on the Autohide feature of the panel (task bar)
Right Click on Panel -> Panel Options -> Configure Panel -> More settings -> Autohide
As long as progress is not showing on the screen (it seems that the problem is the anoying progress icon) plasmashell won't make high use of the CPU.
I turned off almost every desktop effect in system settings but I've not checked if this is correlated as I did this but almost nothing changed on CPU usage

For what it's worth, I had the same problem but only in one activity.
Deleting each applet one by one, the problem seemed to lie in the application launcher.
With some back-traces I found the issue was triggered by a huge recent document list in the `historic' item in the `places' panel.
Forgetting all documents in this list made the CPU load return to normal.

Maybe some knowledgeable developer can dig it further (putting a limit on the number of item remembered?).

Hope this helps.

Regards

dranem wrote:For what it's worth, I had the same problem but only in one activity.
Maybe some knowledgeable developer can dig it further (putting a limit on the number of item remembered?).

If I understand you correctly, this is already a feature - adjust the history time period to a lesser amount or no history at all. I set mine to 1 month so the list doesn't get too long and anything older than that I've probably archived or deleted.

Find this under Settings, Workspace, Activities, Privacy.