bit-tech.net

R600: ATI Radeon HD 2900 XT

ATI Radeon HD 2900 XT 512MB: reference card

Core Clock: 742MHz
Memory Clock: 1650MHz

Just a couple of weeks ago, Nvidia attempted to spoil AMD’s R600 launch with the GeForce 8800 Ultra, which is now available to buy. However, the company didn’t impress us as much as it should have done with an ‘Ultra’ product, especially considering the five hundred quid plus price tag Nvidia’s partners are selling it for!

Many end users were expecting AMD to go right after Nvidia’s GeForce 8800 GTX with a card at a very similar price point, if not slightly cheaper. That’s bizarrely not the case though – AMD has chosen not to launch a product that competes on price with the fully-fledged G80; instead, the company has priced the Radeon HD 2900 XT in line with Nvidia’s GeForce 8800 GTS. AMD didn’t really go into specifics as to why it had chosen not to go after Nvidia’s high-end products, but we’re assuming that it is yield-related.

R600: ATI Radeon HD 2900 XT ATI Radeon HD 2900 XT 512MB R600: ATI Radeon HD 2900 XT ATI Radeon HD 2900 XT 512MB
R600: ATI Radeon HD 2900 XT ATI Radeon HD 2900 XT 512MB
At 240mm long, the Radeon HD 2900 XT is much shorter than the cards that AMD has been demonstrating as the “prototype” R600 graphics card. This is slightly longer than the GeForce 8800 GTS’s PCB, which measures 228mm, but it’s much shorter than the 266mm long GeForce 8800 GTX PCB.

The cooling solution is very similar to the one used on Nvidia’s new 8800-series cards, but instead of being a copper-aluminium hybrid design, AMD has opted for an almost copper-only solution on the ATI Radeon HD 2900 XT. We say almost, because there’s an aluminium portion surrounding the part that comes into contact with the GPU core – this is the portion of the heatsink that secures it to the graphics card.

While we’re mentioning the mounting system in passing – it’s exactly the same design that was used on ATI’s Radeon X1000-series graphics cards. There are four screws that hold a pressure mounted mounting plate onto the back of the card – this helps to ensure that there’s a good contact between heatsink and GPU core.

R600: ATI Radeon HD 2900 XT ATI Radeon HD 2900 XT 512MB R600: ATI Radeon HD 2900 XT ATI Radeon HD 2900 XT 512MB
On top of the copper heatsink on the GPU, both the memory and power circuitry are passively cooled with two large aluminium plates – one on the front, and one on the back of the card. These are clamped to the PCB with eight screws on the back and combined with the copper heatsink on the GPU, they make the Radeon HD 2900 XT quite heavy in comparison to other graphics cards.

On the whole, the cooling solution is reasonably quiet, but it does spin up during gaming sessions and in some cases, it does so quite violently. There were also cases where the fan would occasionally spin up whilst sitting on the Windows Vista desktop, but AMD told us that this is an issue with the drivers we’re using and will be fixed in a future revision.

Even with the 2D spin ups fixed, the Radeon HD 2900 XT’s cooling solution is still not quite as quiet as the cooling solution on any of Nvidia’s GeForce 8800-series graphics cards which rarely spin up, if ever. Even saying that though, the cooler’s noise in 3D environments doesn’t really worry us because it doesn’t sound like the leafblower that was on the Radeon X1800 and X1900 series cards and there is also the fact that you’re either going to have your speakers turned up, or you’ll be wearing headphones while playing games.