The ArtX developed "Flipper" graphics chip runs at a peak fill rate of 800M pixels per second, according to the GameCube hardware documentation. This peak rate includes fogging, Z-buffering, and alpha-blending. Furthermore, additional operations such as trilinear mipmap filtering, S3TC compressed textures, and single-texture maps can be performed at this peak rate. While that figure may seem low in comparison to Xbox´s proclaimed 4000M pixels per second rate, please bear in mind that Microsoft´s figure doesn´t necessarily include Z-buffering, fogging, alpha-blending, or texture-mapping and a number of other performance-draining features. In fact, development sources indicate that Xbox´s realistic fill rate varies between 250-700M pixels per second. For reference the PS2´s fill rate is roughly 800-1200M pixels per second with Z-buffering, alpha-blending and texture-mapping. So, taking everything into consideration all three consoles are about on par when it comes to fill rate, though Xbox may have issues.
(source : ign)
