Using OpenGL with a Displaylink-Adapter leads to high CPU usage

[trepseq]

Hello!

First of all: thank you so much for your work! I have been using Unity/Compiz for a couple of years now and have been very happy with this software. Thank you for making this possible for so many people. God bless you for that!

I have since a couple of weeks a multi-monitor configuration like this:
 - Monitor A: laptop internal monitor
 - Monitor B: external monitor connected directly to the laptop
 - Monitor C: external monitor connected to a USB-DVI adapter which is connected to the laptop

The hardware is:
 - Intel HD3000 in the laptop
 - HP NL571AA USB-to-DVI adapter using a Displaylink chip

My problem is this:
 - Show video on C --> CPU usage of Displaylink driver is high
 - Show video on monitor A or B --> CPU usage of Displaylink driver is equally high

Expected behaviour:
 - CPU usage of Displaylink driver is not high when monitor C is connected and is showing only static content

If I disable the compiz OpenGL plugin using ccsm the CPU load of the Displaylink driver is almost zero if I don't use monitor C, as expected. The problem is of course I then can't drag windows anymore so the desktop is becomes unusable.

According to this post http://displaylink.org/forum/showpost.php?p=79485&postcount=6 this issue is known by Displaylink and has to be solved somewhere else.

My question is: could/should this be solved in compiz? If so, I would be willing to help with the programming if I can.

[Jørn Ølmheim (joelmheim)]

This is a problem for me as well. Ubuntu 16.04 with Unity is my daily driver and we have a dual monitor setup with DisplayLink at work.

I would also be willing to help with the coding and testing of this if required.

[Asbjørn A. Fellinghaug (asbjorn-fellinghaug)]

I'm also experiencing this issue.
If there is something that can be solved from the compiz package that would be awesome. This overall performance slowdown is really annoying.

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Arjan Franzen (afranzen)]

Also affects me; Ubuntu 16.04 with the latest drivers from DisplayLink (19 sept '16)
As soon as a browser with any kind of video content is shown the process eats more then 100% of CPU
and goes back to ~10% when I close the window