AFAIK Fastvid mainly sets the MTRR registers. NVidia windows graphics drivers do this too. Some interesting info here: Wiki MTRR. Wiki Write Combining
This Trick works with the Pentium Pro, II, III and IV at least.
However, I wrote this earlier, based on observations with a Voodoo3:
U now use MTRRLFBE by tikbalang instead of fastvid. And I like it much better. Fastvid sometimes detects the LFB size wrongly (8MB?) and turns off other settings when I just want it to turn on LFB write combining. on top of that fastvid is somewhat slow loading. Ski or Die displays properly with "MTRRLFBE LFB WC", so I can just keep that line in the autoexec.bat.
I notice the original site that hosted MTRRLFBE is gone, so I attach my copy here.
Will I be able to play VESA mode in game such as Quake, and Build Engine games with a PCI Voodoo3 without corruption?
On my Voodoo3 AGP's I run these games fine. And Keen4 too. The Voodoo3 PCI did not appear to behave any different in the brief time that I used it.
I did notice that if I lower the Voodoo 3 speed to much, like 80MHz, I get tearing on the screen. The tearing is also related to the FSB speed of the system, but I cannot remember if higher or lower FSB tended to cause it.
Either way, it was a combination of both.