I was struck with a bout of madness when I was buying my new graphics card because I got a 2GB ATI Radeon 4870x2.
The difference in frame rate between my old Geforce 8800GTX and this new 4870x2 in some games is astounding.
Stalker Clear Sky - between 90 and 140 fps maxed out,
COD4 - between 110 and 150 fps maxed out,
Painkiller - Between 200 and 300 fps maxed out,
Half life 2 - maxed out reflect world 6xAA 16xAF Outside 140 to 240 fps, inside 250 to 300 fps,
Sin episodes Emergence - maxed out reflect world 4AA 16AF between 130 to 280 fps,
Crysis - maxed out on high, 8xAA 40fps
Oblivion - maxed out with 8xAA between 40 and 100 fps outside.
On the whole i'm quite impressed with it but one thing that isn't so rosy is the fan noise. When the fan is on half speed it's not that much louder than the fan on my 8800GTX but when it hits full speed it's really loud, so much so that I had to turn up the volume on Crysis to be able to hear what they were saying.