Is the ATi a Rage Pro or a Rage 128 Pro or a Rage 128?
If it is a Rage Pro, it is a little faster than the G200.
If it is a Rage 128, it is comparable to a TNT1, and quite a bit faster than the G200.
If it is a Rage 128 Pro, it is comparable to a TNT2 or Voodoo3, and way, way faster than the G200.