What system specs (Mac) do you need to watch Quicktime HD trailers?

Factual Questions
1

I went to watch the High Definition Fantastic 4 trailer at Apple’s Quicktime Trailers site, but I couldn’t quite watch it in real time. I have a 1 GHz iBook with a 32 MB Radeon something or other video card and 1.25 Gigs of RAM. What kind of specs will I need to play the 720p video? What about the 1020p?

2

Jest making sure, but you do have QuickTime 7.0 installed?

3

I assume it was installed with Tiger. The video wouldn’t even run without Quicktime 7.0, would it? As it is, it plays, but very jerkily.

4

Apple’s HD gallery system recommendations:

For 1280x720 (720p) video at 24-30 frames per second:
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