Gigabyteís GV-R80P25D X800 PRO card is based on ATIís R420 graphics processor. As its R4xx designation implies, R420 is based on a brand new chip design, this isnít simply a higher-clocked RADEON 9800 XT.
ATI starts with TSMCís 0.13-micron manufacturing process with copper interconnects and low-k dielectric. It is the same process used for ATIís mainstream offering, the RADEON 9600 XT. By shifting to a smaller process, ATI is able to stuff more transistors into a smaller area. This in turn allows ATI to incorporate more transistors, and thus more features into the chip, or you can use the smaller process to make your chip smaller. (This is somewhat akin to what ATI has done with the X300 but thatís another story.)
The end result is a graphics chip thatís cheaper to manufacture and consumes less power, and is less expensive to produce (assuming equal yields). For example, ATI boasts that their X800 PRO consumes less power than RADEON 9800 XT, despite its higher clock speed.
X800 PRO cards compared again
Note the size difference between the two cards
ATI has used the smaller 0.13-micron manufacturing process to cram more pixel pipelines into the X800 line. Whereas the RADEON 9800/9700 and RADEON 9800 XT were all 8-pixel pipeline chips, the X800s sport up to twice the number of pixel pipelines, with the X800 XT Platinum Editions featuring 16 pixel pipelines and the X800 PRO series with 12 pixel pipes. The jump from eight to twelve pipelines increases fill rate by 33% alone, this doesnít even take into account the X800 PROís higher clock speeds, which weíll get into later. High fill rates are crucial for ensuring good performance, especially at higher screen resolutions.
The pipelines are arranged in groups of four, with the X800 PRO having three quad pipes and the X800 XT Platinum Edition having four quad pipelines. Each group is completely independent of the other, so ATI disables the last quad group on X800 PRO boards, although a few hackers have found ways to get around it.
To further differentiate the X800 PRO series from the X800 XT Platinum Edition, ATI clocks both cards differently. X800 PROís R420 core operates at 475MHz while X800 XT Platinum Edition cores are clocked at 520MHz Ė the highest figure in the industry.
ATIís specifications call for both boards to be equipped with 256MB of GDDR3 memory, although the speeds here are also different. The RADEON X800 PRO ships with 450MHz (900MHz effective) memory while the X800 XT Platinum Edition features 560MHz (1.12GHz effective) RAM.
One new feature ATI has launched with the X800 is called 3Dc. 3Dc is a new compression technology ATI has developed for use with normal maps. Normal maps take bump maps to the next level, as they can be used to add much more surface detail. Whereas bump maps were limited to bumpiness, normal maps can be used to add ridges, or peaks and valleys.
Normal maps are being used in an increasing number of game titles, so this feature will play an increasingly important role in the near future. Already Croteam has signed on for Serious Sam 2, along with Valve (Half-Life 2) Irrational Games (Tribes Vengeance), Firaxis (Pirates), Digital Extremes (DarkSector) and CryTek (Far Cry).