HD Video Playback:

In addition to benchmarking these cards in a selection of the most popular games from the last year, we’ve also tested the Radeon HD 2600 XT, Radeon X1950 Pro, GeForce 8600 GT and GeForce 7900 GS in several HD video playback scenarios.

To do this, we’ve used both an HD DVD drive (Toshiba SD-H802A) and a Blu-ray drive (Pioneer BDC-2002BK) so that we can establish how the cards will perform in popular high-definition video codecs like h.264 and VC-1. For our HD DVD movie, we’ve used Superman Returns and for Blu-ray, we’ve used Casino Royale.

In order to play these movies, we needed some playback software that supported both HD DVD and Blu-ray Disc. We turned to CyberLink, whose latest version of PowerDVD 7.3 Ultra supports both disc formats.

We played the films back at both 720p and 1080p by setting the Windows desktop resolution to the required size and then setting the movies to full screen mode. We logged CPU usage over a five and a half minute period and then discarded the first 30 seconds, as we set the video to full screen during this period. This allowed us to get a clean set of numbers, but in order to triple check the CPU load, we ran each test three times – we’ve reported averages here.

A couple of final notes: Firstly, we updated the Nvidia graphics driver to Forceware version 163.11, which includes the latest PureVideo HD post processing effects. To be honest, we didn’t notice any difference in CPU usage between the drivers, but there was a slight image quality improvement with the new driver.

Secondly, we swapped the EN8600GT video card out for another GeForce 8600 GT running at the default clock speeds, but this time one with HDCP enabled. We've labelled the graphics card "Nvidia GeForce 8600 GT" for simplicity, but it should reflect the same performance you'll get from an EN8600GT with the updated PCB that includes the HDCP crypto-ROM. The rest of the system set up remained the same.

HD DVD:

Blu-ray Disc:

It's clear that AMD's Unified Video Decoder is doing its job here, as it requires much less CPU load than the other graphics cards in both HD DVD and Blu-ray Disc playback. Nvidia's second generation video processor is also working well in h.264, as it's supposed to, and there's a small performance improvement over the older video processor on Nvidia's GeForce 7900 GS. That said, during our 1080p VC-1 playback test, the GeForce 8600 GT uses more