xfdesktop tuning

Olivier Fourdan fourdan at xfce.org
Sat Jan 18 15:00:44 CET 2003


I've just committed a couple of changes in xfdesktop regarding speed.

I noticed that xfdesktop was unusable at work where I use a PIV 1.7Ghz
with a GeForceIIMX with 32Mb or RAM and NVidia video drivers.

On that system, xfdesktop dramatically slows down opaque move. As,
technically, there is no reason that mapping a window or using the root
window would make any difference, I was a bit puzzled...

...Until I remembered that gtk-2.x uses double buffering by default,
which means twice as much memory. The XFree driver allocates a given
amount on video RAM to handle pixmaps, and the rest for 3D. If the
amount of video RAM alloted to pixmaps is not sufficient, other data is
stored into system RAM, but transfers from/to system RAM is very slow,
which causes the problem with xfdesktop.

Therefore, I turned off double buffering for the fullscreen desktop

Here is a summary of my changes :

2003-01-18  xfce

* src/: backdrop.c, main.c: * Remove double buffering in desktop
window otherwise gtk allocates twice the size of the screen in
video memory which can show to be unusable even on a GeForce II MX
with 32Mb using 3D because the video RAM alloted to pixmaps cannot
handle the total amount of pixmaps.  * Reduce scale quality to
BILINEAR instead of HYPER because it takes too long even on a PIV
1.7GHz scalling from 1024x768 to 1280x768

Olivier Fourdan <fourdan at xfce.org>

More information about the Xfce4-dev mailing list