Okay, so this really bothers me now for a really long time.
I am Using Ubuntu 16.04.1 64 bit with all latest updates installed. Unfortunately every day after using Google Chrome (and also maybe other apps) for a few minutes the whole UI becomes really laggy and unresponsive in a strange way:
You can move the cursor just like normal and navigate perfectly fine in the browser, but the whole UI lags for example when scrolling through several terminal windows in the taskbar (using the scroll wheel), it takes about 1 second for each window to appear. When taking and dragging a maximized window, it takes also about one second before the window actually gets smaller and can then be dragged (with zero lag). Generally switching between windows takes also about one second each(e.g. changing focus between two windows open side by side).
When completely closing Google Chrome, the issue is resolved. Strange though is the fact, that I have noticed this bug with about any combination of applications sometimes.
I can only assume that something is severely wrong within the system. It's not limited to my installation and can be reproduced on any fresh installation of Ubuntu.
It's not my hardware:
CPU: Core i7 4790k @ 4.5 GHz RAM: 32 GB DDR3 RAM GPU: NVIDIA GTX 970 using the proprietary driver version 367.35
Also, neither CPU nor GPU is being used at all when this issue appears.
Is anyone else experiencing something similar? How can I get debug information for this so I can send some information to the Ubuntu developers?