compositing enabled with Radeon mobility X300

Jethro Tull heavytull at
Fri Aug 5 23:37:47 UTC 2016

From: Thomas L├╝bking [thomas.luebking at]
Sent: Friday, August 5, 2016 9:23 PM
To: Jethro Tull
Cc: xorg at
Subject: Re: compositing enabled with Radeon mobility X300

On Fri, Aug 05, 2016 at 09:24:01AM -0400, Alex Deucher wrote:
> How many displays are you using?  What resolution(s)?

Where did go the original email of Alex Deucher?
I mostly use only one monitor which is the LCD screen of the laptop I'm using
which is has a resolution of 1280 x 800. Sometimes I connect an external LCD
monitor set as extended desktop which resolution is 1440x900. But the problem
with slow acceleration when compositing is enabled is on, either with or without
the external monitor. On the other side, the refreshing of some windows I
described were making the screens more or less scrambled after some time of
work happens ONLY when the second monitor is on. I forgot to mention this last
point in my original email.

This translates to "the output of 'xrandr -q'" ;-)
You might also try other compositors like xcompmgr or compton to rule
out a bug in the one used (xfwm?)

yes I'm using xfwm. But I think this is the thing that is used by XFCE, which
is my desktop environment.

Finally, check the performance on low-resolution (XGA). The device is
short on RAM and compositing quite memory intense (notably in case of GL

Other resolutions than native give an ugly thing on LCD screens. My computer
has 2 GB RAM, the video card is either 64 or 128 MB, and from what I can see in
htop there is always plenty of free RAM available most of the time. I could
nevertheless try low resolution just to see if compositing works better but I'm
not sure that would mean I was short of RAM if the acceleration problem is
partly or totally solved.


More information about the xorg mailing list