3Dfx Voodoo II

You can  put the following in your AUTOEXEC.BAT or in WinNT:s system
variables (through the control panel):

SET SSTV2_GRXCLK=90 (this is the standard setting running the card at 90Mhz)

Now change it to a higher number by changing the line in the AUTOEXEC.BAT to this:

SET SSTV2_GRXCLK=100

You'll need to reboot your computer for the variable change to take effect.

The improvement that you gain through this is minimal (+0.1 fps). So it is really
pointless to overclock the Voodoo².

You can also use the above line in your AUTOEXEC.BAT or pull up the windows registry
(Run / regedit) and locate the registry setting for your Voodoo² board under
HKEY_LOCAL_MACHINE / Software / 3Dfx Interactive / Voodoo 2 and insert a new entry
named SSTV2_GRXCLK under both the GLIDE and Direct3D subdirs found here, set it's
value to 100 in decimal and you're good to go.