xfdesktop tuning

Jasper Huijsmans jasper at moongroup.com
Sat Jan 18 17:33:54 CET 2003


On 18 Jan 2003 15:00:44 +0100
Olivier Fourdan <fourdan at xfce.org> wrote:

> Jasper,
> 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.

Wow that's a pretty big system in my book. I would expect that to
perform a lot better than my Duron 700MHz, ATI Xpert98 8MB video card
... (no I don;t play games :)

> 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
> window.

The speed increase is quite remarkable! 

Let me take this opportunity to mention a hidden feature, which I used
to test this. If you use a backdrop list, running xfdesktop again
reloads the config and thus will change the background (equivalent to
current xfbd behaviour).

> 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
> Cheers,
> -- 
> Olivier Fourdan <fourdan at xfce.org>
> http://www.xfce.org
> _______________________________________________
> Xfce4-dev mailing list
> Xfce4-dev at moongroup.com
> http://moongroup.com/mailman/listinfo/xfce4-dev

IRC channel: #xfce on irc.freenode.net

More information about the Xfce4-dev mailing list