Video playback performance of various video cards
Xbit Labs has a good article up testing video card capabilities during playback of various types of media files. They do a good job of using differents types of clips including H.264, MPEG-2 and DivX.
From the article:
The CPU is loaded quite heavily at that, especially when it comes to the current version of ATI Avivo and H.264, but thatâ€™s not a serious problem considering how much computing power modern dual-core CPUs provide. Still, we canâ€™t explain why Avivo is very fast at decoding H.264 and WMV HD video with a resolution of 1280×720 pixels, but slows down when the resolution is increased to 1920×1080. It may be a hardware problem (some bottleneck in the Avivo architecture that shows up at high bit-rates and resolutions) or a software one (related to the noise reduction and detail enhancement algorithms that canâ€™t be disabled.