Notwithstanding the unofficial arrival of the new graphics card, we can regard it as an established fact that the Radeon HD series has acquired a new model that pretends to be its flagship product. As was to be expected, the Radeon HD 2900 XT 1GB, at least in its version with the standard graphics core frequency, does not deliver anything exceptional in terms of gaming performance. On the other hand, the ATI Radeon HD 2900 XT 1GB in Diamond Multimedia’s implementation is a well-made and appealing product with its specific features and, unfortunately, drawbacks.
It is clear that modern games do not need more than 512 megabytes of graphics memory even for extremely high display resolutions with enabled full-screen antialiasing. The increase of the memory frequency from 1650 to 2000MHz cannot be very profitable for a 512-bit memory bus, especially as the memory subsystem is not the main bottleneck in the R600 architecture. As a result, the ATI Radeon HD 2900 XT 1GB is only 4-5% ahead of its 512MB predecessor at best. More often, the two cards deliver similar performance.
So, there is no wonder AMD decided not to announce the Radeon HD 2900 XT 1GB officially. Delivering almost the same performance as the Radeon HD 2900 XT 512MB but coming at a higher price, this card wouldn’t make a valuable addition into the official ATI Radeon product range. This card is obviously targeted at enthusiasts who are into overclocking. Pre-overclocked versions of Radeon HD 2900 XT 1GB are offered for this category of users as well. Practice suggests that, joined into a CrossFire tandem, such graphics cards can become the means to set new records in 3DMark.
A CrossFire tandem made out of two ATI Radeon HD 2900 XT cards is quite a different thing. Costing about $800-1000, which is comparable to the price of a GeForce 8800 Ultra, this configuration outperforms the Nvidia solution across a number of applications. Our testing has shown that ATI CrossFire technology enjoys a solid support in Windows Vista, obviously due to the high-quality Catalyst driver for the new OS.
It’s only in four out of 23 cases that ATI/AMD’s multi-GPU technology failed to provide a performance growth in comparison with the single card. In the other games from our list the technology worked smoothly, increasing the speed up to 80-90%. We want to specifically note that the AMD CrossFire platform proved to be the only solution to ensure an acceptable speed at 2560x1600 resolution in Call of Juarez and Neverwinter Nights 2. Thus, if not the best solution in the $800 category, the ATI Radeon HD 2900 XT CrossFire is a worthy rival to the Nvidia GeForce 8800 Ultra. Its main drawback is the indecently high level of power consumption, about 320 watts in 3D mode, and it is very noisy, too. These two factors call for a roomy and well-ventilated system case and a high-wattage, expensive PSU.
As for Nvidia’s multi-GPU solutions, the support of SLI technology in Windows Vista is deficient so far despite the release of an appropriate patch by Microsoft. We installed that patch but could not enable SLI mode on our test computer. Anyway, as soon as this problem is corrected, the appeal of the ATI CrossFire platform may lessen somewhat in the eyes of PC enthusiasts.
Diamond Viper HD 2900XT 1024MB GDDR4
- Great performance in contemporary games;
- Numerous anti-aliasing modes;
- Excellent anisotropic filtering quality;
- Superscalar unified architecture with 320 shader processors;
- The industry’s largest amount of onboard graphics memory for a consumer graphics card;
- 512-bit memory access bus;
- Quality multi-GPU support.
- Slight advantage over ATI Radeon HD 2900 XT 512MB GDDR3;
- 16 TMUs and raster processors limit the performance;
- High power consumption;
- High level of generated noise;
- New FSAA modes may wash out the image.