The Radeon X1800 GTO
90 nanometer technology
12 pixel shaders, 8 vertex shaders,
12 texture units, 12 RasterOps processors
256 bit memory bus (512 bit internal ring bus)
500 MHz core, 500 MHz DDR memory (1000 MHz effective)
The Radeon X1800 GTO is a wolf in sheep's clothing: its only purpose in life is to counter the GeForce 7600 GT. Since the X1600 couldn't do that job, ATI took the powerful X1800 graphics processor and crippled it slightly by lowering clock speeds and turning off certain features. The result is a card featuring a brand-new architecture, lowered from 16 to 12 pipelines, but with a full 256 bit memory bus.
Because it is a power-reduced version of a higher-end card, the Radeon X1800 GTO may be the hardware modder's pick of the bunch. Some GTOs have reportedly been successfully modified to full-fledged X1800 XLs with a simple BIOS flash. In addition, the GTO is the only card in the comparison that can have its voltage increased in software, which should allow for much higher overclocking than is possible at the stock voltage.
ATI's X1000 generation is DirectX9c / Shader Model 3.0 compliant and the only hardware architecture so far capable of OpenEXR HDR lighting and anti-aliasing at the same time.
The X1800 GTO is the longest card in the comparison. It is also fairly power-hungry, and requires a dedicated power cable. The X1800 GTO used for testing was an ATI X1800 GTO reference card.