Originally Posted by mlukaszek (Post 79485)

Standard Ubuntu's graphical environment, Unity, causes the screen to be always reported as modified full screen, regardless of which screen changes.

That means: even if nothing changes on the screen which is connected to a docking station, we are still told by the OS to resend full screen update if anything is happening on other screen (e.g. built-in laptop screen).

This gets better in other environments - Gnome3 or KDE for example. I would be interested to see if you experience the same CPU usage if you try other env.

Thanks,
Michal