If you use Linux and have an nVidia card, it is just as important that you install the latest nVidia drivers since the drivers that come with distributions are usually not as effective.
You can download Linux drivers from
this link.
Once you have downloaded the drivers, close X and run the shell script (i.e.
sh NVIDIA-Linux-x86-1.0-7676-pkg1.run) as root. Follow the wizard through to install the drivers.
Note: If you have Riva TNT then you need driver version 7174. It is also recommended for TNT2 and Geforce2.
Once the drivers are installed, find and open your X configuration file (Probably in /etc/X11, called XF86Config or xorg.conf).
Change the
Driver line to say
"nvidia" in the
device section, and in the
module section, make sure that
Load "glx" is there.
Save the file and start X again. With any luck, you should have hardware acceleration and Graal should work nicely.
Note: Graal needs "Direct Rendering" to work properly. You can check if you have direct rendering capabilities by typing "glxinfo" into a shell.