The Radeon HD 2600 XT seems to perform well here, but we’ve already found out in 3DMark05 that the overall score has little to do with the actual capabilities of a graphics card.
The summarized results of the SM2.0 and SM3.0/HDR tests give some more thinking matter to us. The modest result of the Radeon HD 2600 XT – like that of the GeForce 8600 GT – is natural in the first group since its tests correspond to the first and second graphics tests of 3DMark05. The second group of tests depends more on the computing power of the GPU and the RV630 with its 120 shader processors beats the Radeon X1950 Pro as well as the GeForce 8600 GTS that seems to be limited by its 32 shader processors. These results are obtained without FSAA, so let’s check out the individual tests.
As you could expect, the Radeon HD 2600 XT has very low results in both tests of the SM2.0 group. It is slower than the GeForce 8600 GT. It is somewhat ahead of the Radeon X1950 Pro in the second test because the latter is limited by its 8 special-purpose vertex processors while the unified Radeon HD and GeForce 8 architectures do not have this kind of limitation.
The super-scalar Radeon HD 2600 XT architecture shows its best in the SM3.0/HDR tests. The graphics card is only inferior to the GeForce 8800 GTS 320 and by a very small margin, especially in the second test.