Let's start out by checking the stats of our three contestants.
The Radeon X850 XT
ATI Radeon X850 XT
130 nanometer technology
16 pixel shaders, 6 vertex shaders
16 texture units, 16 RasterOps processors
256 bit memory bus
520 MHz core, 540 MHz DDR memory (1080 MHz effective)
The Radeon X850 XT represents the pinnacle of the previous generation of video card technology. As such, it sports 16 pipelines, as well as a full 256 bit memory bus. On the downside, the X850 has an older architecture, and is built on the larger 130 nanometer process.
The X850 is the only DirectX 9b / Shader Model 2.0 card in the trio, which means it can't handle advanced visual features like OpenEXR HDR lighting. Other than HDR, however, there are no features used in today's game titles that would cause a visual difference if used on the X850 XT compared to the newer cards in this article.
The X850 XT is a large card, and is the only one in the comparison that comes standard with a dual-slot cooler to expel hot air out of the back of the case. It is also fairly power-hungry, requiring a dedicated power cable.
The particular X850 XT we tested for this article is an ATI-branded X850 XT Crossfire Edition card, but its clock speeds are the same as any other X850 XT, so they all will perform identically.