14 DAY TRIAL // As far as benchmarks are concerned, it looks like the HD 2900 XT is a bit behind NVIDIA's 8800 GTS 640MB. However, the AMD/ATI newcomer shows abnormal behavior in a series of games. For instance, in "Company of Heroes" it even crushes the 8800 GTX in any resolution and quality setting. Moreover, at 8xAA/16xAF, 2560x1600, the HD 2900XT performs two times faster than the 8800GTS and beats the 8800 GTX by a small margin. While we blame the driver developers for such puzzling results, AMD/ATI acknowledges that their HD 2900XT cards can be further overclocked to make up for the initial performance issues.
Graphics card makers that figure on AMD/ATI's partner list officially announced that they will offer factory overclocked versions of the HD 2900XT reference boards. These overclocked cards are expected to arrive two weeks after the initial 14th of May launch.
AMD/ATI's reference boards are clocked at 745 MHz core and 1656 MHz memory, but rumor has it that the GPU may still be working stably at 840 MHz with the same reference cooler. Not bad for a GPU that heats up to around 80 degrees C. Just think of what a water cooled solution would mean in this situation. My best guess is that, with a suitable water-cooling system, the HD 2900XT GOU core could go beyond 900MHz, with memories clocked around 2000 MHz.
Preliminary tests conducted on the 840 MHz HD 2900XT core reported scores of 11260 marks in 3DMark 2006. Compare this to the 10650 marks scored by the 745 MHz core.
As related to this issue, MSI showcased a watercooled version of the Radeon HD 2900XT, and from what we can see in the picture provided by TweakTown, the cooling system could be covering the memories as well.