My videos in the preview window and external monitor are very choppy in Vegas 5 when I have effects on them. Just wanted some tips concerning hardware fixes for this.
I currently have 3.0 Ghz processor
1gb ram
256mb video card
Take out the effects. You only get smooth playback if you have No effects.
Too much real time processing for any consumer computers to be able to keep up with. If you have more than one video track in the timeline or audio track, try muting what you don't need to see or hear, but as soon as you start adding effects, you can watch the framerate drop, especially if you pile 'em up.
Another trick I've heard about, is to make your video window smaller, but this probably won't help very much. Also, try setting your "preview window" to "Preview auto", if you set it to best, it will lag more.
For critial parts of the video (transitions etc) you can RAM RENDER a loop on the timeline. Just drag a selection across the timeline and press ctrl-B. That will give you full-frame-rate video of that selection. The length of the loop you can use is determined by the amount of RAM you have allocated in Options/Preferences VIDEO tab.