Lagging video?

[The Astroman]

Hey guys!
I just bought a netbook, and I'm trying to view high-def videos on it (it has a 1366*768 screen), however, they sometimes lag.
Unfortunaly, I have a shared Intel GMA 950 chip, which isn't too powerful. I have 2 gigs of RAM and an Intel Atom N280 (1.66GHz).

1) What makes one HD video "harder" to run then another?
I can read some fine, but others lag. Is it the bitrate, resolution, etc.?
2) What is the maximum of the answer to 1) I can play on my netbook? (e.g. maximum bitrate 2000kb/s)
3) How can I optimize my netbook to play videos more smoothly (special drivers, codecs, settings, ...)

 

[The_Other_One]

Yeah... The Atom isn't exactly known for it's video playback abilities. I've yet to really sit down and determine what codecs it likes better than others, but that and bitrate are what really play a role in how smooth the video is. There was actually a video somewhere on Youtube where someone showed various formats playing on an Atom based netbook, and I beleive the 720p videos would play smoothly. They were WMVs if I recall correctly.

As for optimizing, some players work better than others. I've done some tweaks in Media Player Classic but not had too many results.