Maybe you could give some samples, like links to movie (clips) so others can test it. Because the term "HD" is probably
abused and
overused.
Besides, file size is probably not the best descriptor in this case... Think about bitrate, codec instead...
For example, Blu-ray's video stream's bitrate is up to 40Mbps, and can be encoded in 3 different formats. While DVD's is about 10Mbps encoded in MPEG-2.
Reference. The higher the bitrate, the more demanding on the hardware. Different codecs perform and demand
differently too.
FYI, I have no problem playing the 1080p version of "
The Discoverers" on my X61T (C2D L7500 1.6GHz), with some CPU cycles to spare... However, the said video's bitrate is only 8Mbps, and the resolution of the built-in screen is only 1024x768 (dunno if playback at full 1080p resolution will have an effect or not).
The X3000/3100 don't seem to provide
hardware acceleration for VC-1/H.264, so the decoding is done (mainly) by the CPU.
I would like to try out Blu-ray playback but I don't have a drive and media. Nor do I have at this moment a sample H.264/VC-1 clip with bitrate that high. FYI, the
typical bitrate for the current crop of Blu-ray movies is aronud 20-30Mbps.
Cheers and sorry for the excessive use of links... : )