Performance in Synthetic Benchmarks
The ATI Radeon HD 3870 has about the same results as the Radeon HD 2900 XT in the fill rate test. They only differ much when processing one texture, which is easily explained by the difference in their GPU clock rates. The addition of a second and more textures makes the gap between them much shorter, which may be an indication of some fundamental bottleneck in the architecture. The junior model is predictably slower than the senior one, the gap being the largest when they are processing a single texture again.
Interestingly, the Nvidia GeForce 8800 GTX has the biggest advantage over the GeForce 8800 GT when processing the Z-buffer as well as with one or two textures. When there are more textures, the TMU architecture of the G92 chip proves to be more efficient that that of the G80.