Ofcourse not. Would be really silly to say that a Geforce2 or 3 is faster, the fx5900 is a MUCH faster card.
But you have to read this thread.... For a k6 platform to reach the highest score in 3dmark2000, you need the right combination of hardware and software.
And driver 7.76 seems to be the absolute fastest for this benchmark with this platform.
The fastest card that is supported by this driver is the Geforce3. Geforce2 also works almost as fast as both cards are capable of a lot more than the k6 cpu can provide (at the time reviews for the Geforce3 cards were done with 1ghz p3 cpu's).
Grabbing a faster Geforce4 ti, Geforce5 or whatever requires a much later driver that does not have the right optimisations and therefor will be slower. You can overcome this by also grabbing a faster cpu but that is not the point, we want the highest score from super socket 7 AMD.
So the right ingredients up to now according to this thread to reach a high score:
Fastest k6 capable board up to now : Asus p5a-b
K6-3+ cpu
Fast ram: pc133 cl2 with tight bios settings
win95/98/me
DX7
driver 7.76
fastest vga that is supported by that driver: Geforce3
Fastest Ali agp driver
Fastest Reg settings for that driver
Best overclock you can possibly get out of the board/cpu and even overclocking the geforce3 helps.
Run 3dmark2000 with default settings.
Now go on and benchmark it on your system with the fx5900, you will see that it will not even be close. I tried with a ti4600 and i think i got closer to 3k or something like that.
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