From first glance at the Sapphire Radeon X800XT PCIe, its hard to tell that there is any difference between this card and its AGP counterparts. The cards share the same overall design with the same cooling, PCB color, and memory type, with the only difference being in the PCI Express x16 interface and the six pin PCI Express power connector on the back of the card. I’ve mentioned in the introduction that ATI has skipped mass production of their 12 pixel-pipeline R420 part, the Radeon X800 Pro in exchange for their 16 pixel-pipeline Radeon X800XT. To understand how they can switch from pushing the X800 Pro to the X800XT one must take a look at how the GPU of the R420 is constructed. Essentially the R420 GPU is set up into four parts, each with four pixel pipelines. Semiconductor manufacturing is never perfect, and often yields can be very low on high end, high risk parts like the R420 when they are first fabricated.
The outer edges of a silicon wafer usually yield imperfect silicon, for instance R420 GPU’s with imperfect or "broken" pixel pipelines. With the R420’s "quad" sector GPU design, the sectors with broken pixel pipelines can be disabled, and therefore more GPU’s can be produced. This is why we saw the Radeon X800 Pro hit store shelves before the GeForce 6800GT, which uses 16 pixel pipelines and therefore is harder to produce. Unfortunately for ATI, once the GeForce 6800GT was released in mass numbers, the demand for the Radeon X800 Pro deflated among the enthusiast community and ATI was left banking on Half-Life 2 performance, which we have only been able to gage synthetically so far.
Now that the R420 has been at full production for almost five months, producing 16 pixel pipeline parts has become much easier, and hence today we are reviewing a Radeon X800XT PCIe instead of a Radeon X800 Pro PCI graphics card.
When we turn the card around we see the remaining four (eight total) Samsung 1.6ns GDDR3 memory chips, the same memory chips used on the Radeon X800XT Platinum Edition (just clocked 60MHz slower at 500MHz). Also one should note the ATI Rage Theater chip on the bottom right portion of the picture, allowing for VIVO functionality on the card.
When we take a look at the back side of the card we can see the new six pin power connector that is used on all PCI Express graphics cards. The yellow connector next to it is for front panel VIVO connectivity, a great idea that I hope more case manufacturers implement in their cases.
And of course the Sapphire Radeon X800XT PCIe uses the standard VGA, S-Video, and DVI outputs.