DVD acceleration

ATI has historically had some of the best hardware-accelerated video playback in the industry, so I had high hopes that the DVD performance of this card would be outstanding. This will be one of the few shipping video cards with what is known as "motion compensation", a DVD-specific feature designed to reduce the CPU burden of DVD playback.

The bundled ATI DVD Player 3.0 is exceptionally good, and has replaced all of the other software DVD players on my drive as the player of choice. I was able to install the ATI DVD Player under both the TNT and the Rage 128 cards, and this was the original intention by ATI, to design and support a solution that can run on competitive hardware. With that, I proceeded to do some informal CPU usage testing.

My sample title was the excellent Bond flick Goldeneye. I used the Microsoft kernel toy WINTOP.EXE to show CPU usage of all running tasks, and played through the first five minutes of the first action scene in Goldeneye. I apologize that my benchmark isn't more scientific, but I did run through it three times on each card to make sure I got a good feel for average, minimum, and maximum CPU usage during playback.

The test PC was a P2-450 and 256mb of RAM, and the DVD is a Sony 5x IDE model.

nVidia TNT: Between 45% and 65% CPU usage, average of 55%
Rage 128: Between 35% and 60% CPU usage, average of 45%

The ATI card reduced the load on the CPU by a consistent 10 percent. I have to admit I was a little disappointed, since I was expecting a 25 percent or larger reduction in CPU usage over the TNT. As for image quality, the ATI card did have a slight edge. With fullscreen playback, I honestly couldn't see much difference between the two cards; after all, they are both bilinear filtering the image to smooth it out before displaying it at high desktop monitor resolutions. However, the Rage presented fewer interlacing artifacts during high-contrast, fast-motion scenes, and given ATI's excellent reputation in video playback and their focus on DVD as a feature of the card, I'm not too surprised. However, if you are looking for a dramatic difference in image quality, I recommend changing software DVD decoders - I saw a far larger image quality difference in switching from Xing to ATI's DVD player software than I did in going from the TNT to the Rage 128.