I am editing footage from the Canon H1 and am using an HP computer 3.0Ghz processor, 1.5gigs of ram and still the footage stutters and won't play smoothly. if an unedited clip is long enough, it will catch up and play in real time, but the moment you start cutting, the short clips bog the system down. I am using Sony's Vegas as my NLE

What gives?

Where can I get minumum specs for smoothly editing HD content?