This driver has a special requirement that needs to be fulfilled before it
will work: you need Glide installed. At the time of this writing, it may
be found at <http://glide.sf.net/>.

Also, you need to tell the X server where the libglide2x.so file is placed by
making a soft link in the moduledir directory (usually /usr/lib/xorg/modules)
that points to the libglide2x.so file. For example, if your libglide2x.so file
is in /usr/lib):

         # ln -s /usr/lib/libglide2x.so <moduledir>

If you have installed /dev/3dfx, the driver will be able to turn on the MTRR
registers (through the glide library) if you have a CPU with such registers
(see <http://glide.xxedgexx.com/MTRR.html>).
This will  speed up copying data to the Voodoo board by as much as 2.7 times
and is very noticeable since this driver copies a lot of data...
Highly recommended.