Board inspection
There are two ways to design cards PCI Express cards. NVIDIA, if we exclude the new GeForce 6600 GT, has chosen to add a bridging chip on to an AGP design. That approach doesn't bring out the best features inherent to PCIe, namely a far smarter architecture and greater overall bandwidth. However, NVIDIA has also realised that the benefits of true PCIe aren't that great right now.ATI has gone the whole nine yards and opted for true PCIe GPUs right from the off. That means no bridging chips, a lack of associated latency incurred by bridging, and potential for oodles of bandwidth between GPU and host CPU processor.
One obvious advantage of not having to use a bridging chip is PCB economy. The Radeon X800 XT PCIe GPU is ATI's finest, and the AX800XT/2DT is ASUS' finest PCI Express card. You wouldn't think it from the above picture. A full 16-pipe rendering setup, massive memory bandwidth, and stellar overall performance in what is essentially a small, single-slot, innocuous-looking card.
The side-on shot shows ASUS using a large slab of copper cooler to keep the R423 GPU and memory chips cool enough. Surface area is augmented by using a number of thin fins. On the right-hand side, just above the 6-pin PCIe power connector, ASUS uses heatpipe technology to transfer heat towards the rear. Decent, thoughtful design.
ASUS hasn't forgotten aesthetics. The cooler contains LEDs that give off this pleasant blue glow. Perfect for users with windowed cases. Irrelevant for those without.
The cooler covers both GPU and GDDR3 memory chips concurrently. It feels reassuringly heavy once removed. Looking at the underside reveals decent contact with the GPU. ATI/ASUS' use of a raised shim dictates that memory isn't directly in contact with the copper. Rather, 4 pads provide the necessary conduit.
A view of the exposed core and RAM shows a generous helping of thermal goo atop of the R423 core. A single-chip design is the intrinsic beauty of a native PCIe design.
Dual DVI goodness on an ATI card. The proliferation of DVI-equipped flat panels makes having 2 DVI-I ports a wise move. CRT monitor users needn't worry, of course, as DVI-to-VGA dongles allows one to drive two HD15 displays, too. ASUS has decided to forego VIVO on this model. That's a shame when one considers how solid the rest of the package is.
The back shows a probable location for a VIVO ASIC, across to the right. It's interesting to note that ASUS hasn't bothered with using a dual-sided copper cooler here. It looks very much like a reference Radeon X800 XT PE AGP version.
That thought is dispelled with a close-up look at the RAM chips. A regular AGP-equipped X800 XT card runs with core and memory speeds of 530MHz/1120MHz, respectively. ASUS has chosen to use 2ns (1000MHz-rated) Samsung GDDR3 memory chips on the PCIe model. These are identical to the ones found on most AGP X800 Pro/XT models. Further, core speed has been restricted to 500MHz, so whilst this card enjoys a full 16-pipe rendering setup, clock speeds are a touch lower than expected. Performance, then, should hover between Pro and XT PE levels.
