I have been using a Canopus Pure 3D voodoo 1 card for about 6 months. I have had this card through 3 computer systems from a cyrix pr-166+, a pentium 166, and now a pentium II 266.
If you also have a voodoo1 card, dont go out and upgrade you cpu to get better frame rates. (unless you have a really slow cpu already). To give you all a performance difference with this game and different computers, here are the #'s I got with quake II on my systems with a voodoo1 card, running the timedemo 1, demo1.dm2 map.
Cyrix pr-166+ with vx board and 32mb sdram: This setup could only achieve a mere 12 fps with the voodoo1 card at 50mhz, with quake II at 640x480 resolution.
The Pentium 166 with hx board and 96mb of edo ram: This setup was capable of achieving 19.5fps in quake II at 640x480.
The Pentium II 266 with lx board and 64mb of sdram: This setup for me is capable of 22.5 fps in quake II at 640x480 resolution. I have done the most tweaking using the pure 3d in this system, and by seting the pure 3d driver clock speed control to 58 mhz, I am able to push over 26fps in quake II.
As you all can see, there is not much of a performance increase from a pentium to a pentium II with a voodoo1 card. But the difference between a pentium and a cyrix with the same pr rating is significant.