Ok, I just got a PNY GTX-470 "Performance Edition"
I plugged it all in, set up the drivers, and started up crysis.
I maxed that game out and im only getting about 15-25 frames. it will work choppy for a second and then pretty smooth. same with gtaiv.
it seems only a little bit better than my old 4850 like 20% better. maybe less

I have a pretty old cpu and a pretty low end motherboard. but i know that wouldnt hold the graphics card back too much. maybe the 470 is just not as good as i thought.

here are my specs.

ecs a780gm-a motherboard
athlon 64x2 6400+ 2.7ghz
2gb ddr2 800mhz
WD caviar black 1tb
pny gtx 470 1.25 gb
ultra 650 watt power supply