The performance difference between ATI Radeon HD 2900 and Radeon HD 2600 is known to be unjustifiably huge. Today we are going to take a look at the attempt to build a bridge between the two undertaken by AMD's graphics division. Although this solution will only last for a short period of time, it is worth checking out. There is a big gap between technical characteristics of top-end and mainstream solutions currently offered by the consumer 3D graphics industry. Of course, there has always been that kind of gap, but it has never been as wide as between the ATI Radeon HD 2900 and Radeon HD 2600. The same is true for NVIDIA's GeForce 8800 and GeForce 8600 families. - X-Bit Labs

ATI Radeon HD 2900 PRO 512MB Video Board Review

Historically, ATI and NVIDIA both released cheaper graphics cards based on cut down versions of top performance GPU's. Although not optimal in terms of manufacturing cost, this approach is still better than the production of dual-chip solutions with two less advanced GPU's just because it doesn't require developing a unique PCB. That's the way the ATI Radeon HD 2900 PRO was born. Contrary to the expectations of many gamers and mass media, the configuration of the R600 chip the new card is based upon has not been cut down. The clock rates of core and memory are that suffered from the reduction.

In other words, the ATI Radeon HD 2900 PRO is in fact an ordinary ATI Radeon HD 2900 XT with 512MB or 1GB of GDDR3 memory accessed across a 512-bit memory bus and a graphics core frequency of 600MHz. The reduction of the memory frequency is negligible. According to the manufacturer, the ATI R600 chips are clocked at 24 different frequencies, but the difference between the frequencies of its subunits must be small as opposed to NVIDIA's chips. As a result, the reduction of the frequencies is going to have a serious effect on the performance of the Radeon HD 2900 PRO in games.

The ATI Radeon HD 2900 PRO is undoubtedly a success. Priced at only $249 it provides an acceptable speed in most of our tests as opposed to graphics cards with the mainstream GPU's RV630 and G84. We really doubt that even a Radeon HD 2600 X2 would match the performance of the new card because it would be inferior to the Radeon HD 2900 PRO in the amount of ALU's and raster back-ends as well as in memory subsystem performance. We don't even count in the possible compatibility problems the dual-chip solution is sure to have.

Considering the imminent arrival of graphics cards with ATI’s new RV670 core, there is no sense in producing the Radeon HD 2600 X2 in mass quantities. The Radeon HD 2900 PRO, even in small quantities, can successfully fill in the gap between the Radeon HD 2900 and Radeon HD 2600 families. It fulfils this purpose even better than the sophisticated Radeon HD 2600 X2 with all its potential problems. As for drawbacks, the ATI Radeon HD 2900 PRO has them just like any other product, but the most important one is the low availability meaning that this rather a limited product as far as ATI is concerned.

This may also affect the retail price of the card. Besides, the card has all the drawbacks of the ATI Radeon HD 2900 XT such as high power consumption, a high level of noise in 3D mode, a bottleneck of 16 TMU's which are also clocked at a reduced frequency and architectural peculiarities that make the card’s performance dependent on driver optimizations. And still, with all these minor problems, the ATI Radeon HD 2900 PRO is perhaps the best graphics card in the $249 price category, if you are lucky to find it selling for this price.