put it this way:
i have benchmarked a lot of video cards on my pc, here are some 3D mark scores for you:
GeForce FX5200: 3843
GeForce 4 MX 420: 4075 (6% greater than the much newer FX!)
GeForce2 Ultra: 5457 (42% greater than the FX, and came out in 1999/2000)
ATI Radeon 7500: 5472 (42% faster)
GeForce4 MX 440: 5633 (47% faster)
ATI Radeon 9000: 7312 (90% faster)
GeForce3 Ti 200: 7516 (96% faster than the new FX!)
Ati Radeon 9500/9700: 12703 (231% faster than the FX, and i got it over a year ago for $150 in a retail store)
imagine what a 9800 pro could do in a G5...
As you can see, the new FX cards are dissappointing, considering that nvidias much older stuff can whip its tail.
I dont know why apple cant just put the ati cards in all the PBs, i mean theyre charging enough already, and the radeons they put in the higher ones arent any kind of powerhouse. Why do they insist on putting 3+ year old technology in a $2000 laptop?
granted this is PC stuff, but you get my drift. nvidia has actually caught a lot of crap about the FX cards because they "optimized" their driver set to benchmark higher on certain tests than they would ever get in real life.
These scores were all benchmarked on my Athlon XP 2400 machine with a Soyo Dragon Kt400 ultra motherboard and 1GB DDR400 memory. I borrowed these cards for a benchmark for one of my computer architecture classes.
i'm in my 4th year of computer science in college. Yes this is a simple comparison, and believe me, i can get as technical as you want.