Different drivers can give MASSIVE gains, that's why it is so hard to compare scores between different machines with different hardware and different software...
Good example is the ''aiming for the stars'' thread here on Vogons where we try to reach record scores with k6-3+ cpu's in 3dmark2000. link AMD K6 3DMARK, aiming for stars.
There you can see scores from a k6-3+ with a geforce2 or geforce3 in 3dmark 2000 of around 5000 3dmarks (not talking about cpu marks). Greatly because of the 7.76 driver of Nvidia.
To be able to beat that score with a much faster card (like a geforce4 ti or even 5950ultra, 6800ultra or faster) i need a fast Tualatin cpu or higher just because of the later driver beeing much slower in 3dmark 2000 and the Nvidia 7.76 driver is not supporting those newer cards.
asus tx97-e, 233mmx, voodoo1, s3 virge ,sb16
asus p5a, k6-3+ @ 550mhz, voodoo2 12mb sli, gf2 gts, awe32
asus p3b-f, p3-700, voodoo3 3500TV agp, awe64
asus tusl2-c, p3-S 1,4ghz, voodoo5 5500, live!
asus a7n8x DL, barton cpu, 6800ultra, Voodoo3 pci, audigy1