Originally posted by david_1475
Each card is capable of flogging the other, depending on the game being played.
That pretty much sums it all up. The hardware specs rarely mean ANYTHING when it comes to video cards, especially when comparing nVidia and ATi since its like comparing Intel and AMD. And don't compare the X800GT to the other X800s, especially the XT and XL. The X800GT was designed to be a midrange videocard, and performs MUCH worse than the others, while the X800XT and X800XL were designed to be performance (though they didn't perform that well, lol).
6600GT has SM3 and some other things going for it that the X800GT doesn't.