Sony Vegas: Guidelines for Fast Preview Speed (from Sony Vegas forum, http://www.sonycreativesoftware.com/forums/ShowMessage.asp?MessageID=758370)
- Match project properties exactly to your source footage. Use the “match” feature to do this. Failure to have these settings correct is the biggest reason for slow timeline playback.
- Don’t use higher preview resolution than necessary. Use Auto instead of Full, and use “preview” or “good” instead of “best,” especially when smooth timeline performance is more important than being able to see every last detail.
- Turn off “scale video to fit preview window.” This doesn’t make a huge difference, but it helps.
- Make your preview window smaller.
- Set “Deinterlace Method” in “Project Properties” to “Interpolate” instead of “Blend”.
- Try setting “Thumbnails to show in video events” in “Video” preferences to “None”, especially for multicam projects.