X-bit labs

Two Diamonds: ATI Radeon HD 2900 XT 1GB CrossFire Review (page 21)

Category: Video

by Alexey Stepin , Yaroslav Lyssenko, Anton Shilov

[ 09/11/2007 | 10:13 AM ]

Futuremark 3DMark06

The CrossFire tandem enjoys a big lead over the other test participants, scoring over 13.000 points. The best result among Nvidia’s single-card solutions is 11,462 points. Since both models of ATI Radeon HD 2900 XT have the same result, a CrossFire tandem made out of two cards with 512MB of graphics memory will be just as effective in outperforming the GeForce 8800 Ultra.

As we had anticipated, the pair of Diamond Viper graphics cards comes out the winner in both categories of tests, but it enjoys a bigger lead over the GeForce 8800 Ultra in the SM3.0/HDR tests. The total of 32 TMUs and 32 raster processors prove to be enough to get rid of the R600’s bottleneck whereas the combined power of 640 shader processors leaves no chance to the opponents where sheer computing is necessary.

The results of individual tests launched at high resolutions with enabled full-screen antialiasing produce a somewhat different picture. The CrossFire tandem doesn’t take first place in the first test although looks competitive against the GeForce 8800 GTX/Ultra. As for the single performance of the ATI Radeon HD 2900 XT cards, they are inferior even to the GeForce 8800 GTS, and the 1GB model is considerably faster than the model with 512 megabytes of GDDR3 memory. The computing capabilities of ATI’s architecture are not called for here.

The SM3.0/HDR tests are quite a different story. Here, the two Diamond Viper HD 2900XT 1024MB GDDR4 cards working in CrossFire mode deliver almost two times the performance of the GeForce 8800 Ultra in both first and second tests. Moreover, both versions of ATI Radeon HD 2900 XT are very close to the GeForce 8800 Ultra in single-card mode in the first test where they are limited by the number of texture and raster processors and outperform the Nvidia card significantly in the second test, which is not so sensitive to the texture-mapping speed.

All in all, the 3DMark06 results confirm the fact that the ATI Radeon HD 2000 architecture is better suited for modern gaming conditions that require a high computing capacity from the GPU. On the other hand, the fact that the R600 has got one bottleneck – a too small number of texture and raster subunits – is confirmed as well. The answer to the main question of this review is clear, too. The ATI Radeon HD 2900 XT CrossFire configuration is quite a worthy alternative to the Nvidia GeForce 8800 Ultra.