HD Video Playback:

Given that Zotac's GeForce 8600 GT ZONE Edition video card is designed with HD video playback in mind, we also tested the card against its competition 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.

The system setup remained the same as the one we used for our gaming tests, but given that both AMD and Nvidia are constantly working on improving HD video image qualuty, we updated the graphics drivers to the latest available at the time of the review. In the case of AMD, that was Catalyst 7.9 WHQL and in the case of Nvidia, we used Forceware 163.69 WHQL.

HD DVD:

Blu-ray Disc:

AMD's Unified Video Decoder is working much better than Nvidia's second generation video processor in both h.264 (which Nvidia accelerates) and VC-1 (which Nvidia doesn't accelerate). The VC-1 codec isn't quite as intensive as h.264 and therefore it isn't quite as crucial to accelerate it as content encoded in h.264, which struggles to play smoothly on the previous generation graphics hardware. However, even despite the lack of acceleration, the GeForce 8600-series cards manage to reduce CPU usage a little compared to the GeForce 7900 GS and Radeon X1950 Pro.