Matrox Mystique G200 slow

[haddock]

Hi

Can someone please give me some straight advice on how to set up my Mystique G200 (what do I need to enable/compile). I've compiled all the G200 options in the menuconfig and load the modules via modules.autoload (and they do appear during bootup). the x11config contains 'mga' as device.
However, there is no difference in speed between using these modules and using the standard vga driver. On my OS/2 partition the matrox performs very fast - under Linux (Gentoo) the graphic is extremely sluggish.
I've searched all of the gentoo forum but couldn't find an answer to my question. Apart from the graphics everything works extremly fine - gentoo is really a great distro.

thanks for your help
haddock