GeforceTweak can enable Sideband Addressing in the nVidia drivers. You can get the program at <A HREF="http://www.guru3d.com" target="_new">http://www.guru3d.com</A>.
I have to warn you that, although SBA seemed to give a modest performance boost with my Geforce2 in the current session, my system would boot to a blank screen after a restart or shutdown. This force me to boot to Safe Mode and turn off SBA with GeforceTweak just to be able to boot Windows normally.
This wasn't very practical for a small performance gain.
That was with Windows 98SE and Detonator 12.xx & 14.xx. I don't know about other versions of Windows or Detonators.
<b>I have so many cookies I now have a FAT problem!</b>