Radeon HD 2900 XT GPU
R600 is AMD's first range of top to bottom DirectX 10 graphics cards with fully certified support for Microsoft's Windows Vista operating system. While DX10 GPU support might not be very important right at this moment, soon it will be a requirement to experience the best graphics potential from current games, which are awaiting DX10 patches, and upcoming games such as Crysis, Alan Wake and Unreal Tournament 3. Sadly it is basically impossible for us to provide comparative DX10 benchmark numbers between AMD and Nvidia graphics cards at the moment - AMD gave the press a DX10 benchmark demo of Call of Juarez but it does not work properly on Nvidia graphics cards at this stage. 3DMark07 is not too far away and DX10 games and patches will come out soon (starting from June onwards) but until that time, we are unable to test this new API's performance.
R600 GPU is also the first out of the major GPU players to introduce a smaller 65nm manufacturing process but still manages to pack in a massive 700 million transistors for the top model. Keep in mind that the high-end HD 2900 XT uses 80nm process technology from TSMC but the HD 2600 and 2400 series use the more power efficient and cooler operating 65nm process. It is said that AMD will launch the faster R650 (possibly with two models, HD 2950 XT and XTX) in Q3 of this year that are also based on the improved 65nm process, which will allow AMD to ramp up clock speeds and fight harder against Nvidia. You were thinking it and you are right - it will probably only be three or four months before your brand new Radeon graphics card has been replaced with a faster model but that is just the way things seem to be now, like it or not.
It is also the first with 512-bit memory interface (compared to GeForce 8800 with 384-bit and 86.4GB/s bandwidth) which will increase memory bandwidth throughput (stock speeds push out 106GB/sec) without having to have the memory frequency tuned up as high or relying on more expensive GDDR-4 memory. For instance, the memory clock speed of the HD 2900 XT is just 828MHz (or 1656MHz DDR) whereas the 8800 GTX operates at 1800MHz DDR with its slower interface. Using 320 processing units at a core clock speed of 742MHz with two FLOPs per unit, it is able to process data at 475 GigaFLOPS.
It is enough to make the new HD 2900 XT up to 150% faster than the old Radeon X1950 XTX in some ultra-high-resolution gaming tests, according to AMD press documents. Crossfire dual-graphics support is not going anywhere and of course, it is fully supported by the HD 2900 XT.
AMD may well have added "HD" into the product name since it is not only able to process video but also audio over HDMI. Details are unclear at this stage but this card will be able to output up to 5.1 surround sound through the DVI port using a special DVI to HDMI adapter, which is also a first - previously if you used a DVI to HDMI connector on older graphics cards, it would just carry video signals. AMD has not been very forthcoming with info about how the sound part works but apparently there is an audio chip on the card that is able to achieve the feat. AMD has done this to gain Microsoft Windows Vista Premium Logo certification, as requirements for HDMI systems state that you cannot split the audio output - e.g. HDMI carrying video and audio and optical or whatever else also carrying the signal to your speakers.
That finishes the summary on the GPU itself - let us move to the actual card now. Next page please!