X-bit labs

ATI RADEON X800: R420 Totally Exposed (page 10)

Category: Video

by Tim Tscheblockov , Alexey Stepin , Anton Shilov

[ 05/04/2004 | 06:42 AM ]

VIDEOSHADER: Video and HDTV

Unlike NVIDIA developers, who provided their offspring, NV40 GPU, with special functions for video streams processing, ATI Technologies’ engineers decided to let well alone and left everything as is. In other words, R420 features the same video processing mechanisms as R3x0/RV3x0 family. However, it doesn’t mean that R420 features weak video processing algorithms. Since the times of RADEON 9700 PRO, ATI graphics adapters can use pixel processors computational power – VIDEOSHADER technology – for this purpose, so RADEON X800 doesn’t have any issues about video processing. VIDEOSHADER helps the graphics processor to perform de-interlacing, reduce noise level, convert color spaces, and apply some sort of anti-aliasing, which removes block artifacts typical of MPEG-4/DivX data compression methods.

Like in case of any other new graphics chip, we tested ATI RADEON X800 during the playback of videos in the whole bunch of different formats: HDTV, MPEG-4/DivX and MPEG-2/DVD. In all three cases, we used Windows Media Player 9.

For your convenience we summed up all the test results for R420, NV40 and DeltaChrome S8 in pretty easy to read diagrams:

During HDTV playback, we discovered no special surprises: the CPU utilization appeared quite acceptable even despite this high quality video stream. The GeForce 6800 Ultra based graphics card couldn’t pass this test OK, because of some driver issues: the CPU utilization always grew up to 100%.

We played the movie in 1440x1080 resolution with 8Mbit/sec bitrate.

When we played the movie encoded with DivX in 640x480 resolution, the newcomer also performed pretty well, although the CPU utilization grew somewhat higher than by S3 DeltaChrome S8 Nitro working in nominal mode. When we enabled Chromotion engine to the full extent, the S3 solution won the first prize.

The DVD playback test also caused no problems. Moreover, RADEON X800 XT performed best of all among the graphics cards that do not use any special enhancements for video decoding algorithms. Even when Chromotion engine of S3 DeltaChrome S8 Nitro was enabled, the CPU utilization got just a tiny bit lower.

As for the image quality during video playback, it was almost the same in al cases, and we do not have any complaints about it.