As we mentioned in our previous article HD H.264 decoding on a Mac currently requires a G5. Even the dual G4 Power Macs are not supported. The new webpage reflects this requirement, and all the clips require a G5 to play.
However, it seems that previous article was incorrect as to the requirements for 1920x1080 HD playback, which are now listed:
For 1280x720 (720p) video at 24-30 frames per second:Judging by tests by various people, it seems the above specs are a little conservative. Clean playback can be had on lesser G5s. Note that the clips can technically be played on G4 Macs, but unfortunately, not very smoothly most of the time.
* 1.8 GHz PowerMac G5 or faster Macintosh computer
* At least 256 MB of RAM
* 64 MB or greater video card
For 1920x1080 (1080p) video at 24-30 frames per second:
* Dual 2.0 GHz PowerMac G5 or faster Macintosh computer
* At least 512 MB of RAM
* 128 MB or greater video card
Thanks to the guys who reported that their dual GHz Power Macs will play back 720p24 material with no dropped frames. Using this info and info from a thread at Ars, I've posted a new article listing real-life requirements.