Originally posted by Cerulean
Yes, the X1900XTX has a high core clock speed. comparing those two Geforce cards is like comparing the old ATI Radeon 9600 with the 9700. Why would you spend the extra money if you really aren't going to notice the difference?
Your missing a major component of a GPU, the pixel pipelines.
X1900XT = 16 pipelines / 625 core clock speed
7800GT = 20 pipelines / 400 core clock speed
7800GTX (256) = 24 pipelines / 430 core clock speed
7800GTX (512) = 24 pipelines / 550 core clock speed
7900GT = 24 pipelines / 450 core clock speed
7900GTX = 24 pipelines / 650 core clock speed
(these are stock clocks from ATI's and nVidia's reference models)
Each pipeline is running at the GPU's core clock speed.
7900GTX 24 x 650 = 15,600
X1900XT 16 x 625 = 10,000
But since the architecture of the X1900 allows 48 shader proccesses per clock versus 24 that the 7900GTX has so this allows the X1900XT to proccess graphics better. The 7900GTX will outperform the X1900XT in non-shader intensive games, but like FEAR has shown us the X1900XT will outperform the 7900GTX in games with a lot of shaders. As more games start to use more and more shaders, like a fine wine, the X1900 XT will get sweeter with time.