What sytem spec you got ?
Voodoo 3DFX were good in their day ( Used to have a Voodoo Banshee ) but things have moved on.
Unless you have a really slow /old cpu you will be better off with a modern card.
GPL is very dependant on cpu usage and does not leave the graphics card much to do. So if you have low frame rates etc... you need to upgrade to a modern fast cpu.
My system is almost 3 years old now ( AMD64 Athlon 3200+/Nvidia 6800GT ) but it runs GPL and all current mods with good frame rates at high detail settings.
Edited by paul skingley, Feb 16 2008 - 08:29 AM.