ATI R420: Shader Model 2.0 in Need for Speed?

On May 4, ATI Technologies rolled out its R420 chip as a response to NVIDIA?s earlier announcement (For more details about ATI R420 read our review called ATI RADEON X800: R420 Totally Exposed). Like the competitor, ATI was evolutionary, rather than revolutionary with the new chip, basing it on the R300 architecture, although revised, improved and stripped of some earlier drawbacks.

Besides everything else they made the RADEON X800 using a new 0.13-micron technological process with the so-called low-k dielectrics. As a result, the chip was more compact and worked at a higher frequency than the competitor from NVIDIA. The relative simplicity ?only about 160 million transistors ?and the new tech process helped to reach frequencies of about 500MHz. Curiously, the RADEON X8xx was to come out with 12 pipelines, but ATI changed its mind and released a 16-pipelined processor, like the NV40.

As for new technologies, there were no revolutionary innovations in the R420 ?things had just been enhanced a little. The organization of the pixel pipelines has changed ?16 pipelines were split into 4 groups, each of which could process 4 pixels at once. The HyperZ technology was once again improved and dubbed HyperZ HD. Besides, ATI equipped the R400 architecture with a new algorithm of normal map compression called 3Dc.

Two graphics card models were announced, with two more approaching. At the end of the year the RADEON X800 family included 9 models, which makes it the biggest family in ATI?s line-up.

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All new RADEONs were equipped with a single power connector and a standard set of outputs (DVI-I, D-Sub and S-Video). As for the heat dissipation, the new chip from ATI, thanks to the improved tech process, proved most unpretentious and lived on with a modest cooler, even of a smaller size than the cooler installed on the RADEON 9800 XT. The power consumption parameters were also better than with the GeForce 6800 Ultra ?even the top-end model, RADEON X800 XT Platinum Edition, came with a single power connector.

The evolutionary approach of ATI Technologies towards developing the new GPU proved to be correct. As our tests showed, the new RADEON X800 family was most successful in terms of performance, often delivering more speed than the GeForce 6800 series (for the detailed benchmark results see our article called Clash of the Titans: ATI RADEON X800 PRO and ATI RADEON X800 XT Against the NVIDIA GeForce 6800 Ultra). The availability of the RADEON X800 was also better than with the GeForce 6800 ?these graphics cards appeared in retail soon after the announcement, although at rather steep prices.