I installed Slack 12.1 recently and I've been trying to decide which WM to use and such. I like XFCE and Openbox, and I'm leaning toward openbox for a simple base. I also tried out compiz swapped in for xfwm4 just to try out some of the effects. I want to try using openbox with xcompmgr for transparency, but it's really slow!

If I run glxgears in fluxbox or xfce plain, I get over 15000 fps.
...in xfce with compiz I get about 8000 fps.
...in fluxbox or xfce with xcompmgr I get between 700 and 1500 fps!
...in xfce with xfwm4's compositing enabled I get 700 to 1500 fps also.

Isn't xcompmgr supposed to be a very basic compositor? It should at least be faster than compiz, right?

I have an nvidia 7900gs running on the latest nvidia driver. My xorg.conf contains:

Section "Device"
Identifier "nVidia Driver"
Driver "nvidia"
Option "AddARGBVisuals" "true"
Option "AddARGBGLXVisuals" "true"
Option "NoLogo" "true"
Option "DisableGLXRootClipping" "true"
EndSection

does anyone know why xcompmgr might be this slow?

(I posted this in the slackware thread and suggested it be moved here but it hasn't been done yet. If a mod would like to, please delete the thread there!)

Xcompmgr is just a different compositing manager. Compiz uses OpenGL and faciliates a certain X-feature which hadn't been around when the xcompmgr was developed. Xcompmgr was only meant to be kind of a case study to show what's actually possible with compositing. It works differently.

And so does Metisse, KDE 4, Metacity and Xfce - they all implemented their own stuff, so you might experience different levels of stability and speed.

but it seems like 15000+ fps with no compositing dropping to 700 when using xfwm4's compositing is a really drastic change... like I'm doing something wrong.

Could anyone else post their glxgears changes when using xcompmgr vs not? I get about 1700 fps in openbox with xcompmgr -c, and 16000 without.

Are there any other compositors that work with your window manager like xcompmgr, rather than replacing it like compiz?