i have found that rendering either the whole project as an uncompressed avi or quicktime movie (animation codec), OR rendering sections as new tracks first THEN rendering this new piece of media to mpeg cuts down render time.
well it works for me. The processor doesn't need to work out all the vegas effects etc, then do the compression to mpeg aswell. This way you have a hardcoded video that is one layer, then a second render coverts this to mpeg. it is quite suprising to see how fast this second render takes.
Of course there is a draw back...isn't there always...you NEED alot of space.
I would say for a 12 minute project with effects etc you would need near 20 gig for the uncompressed file..that may not be an issue, but something to consider...

The most important thing you can do to decrease rendering times is to render to a separate physical disk.

If you are rendering to MPEG, I don't think you will save time rendering first to an AVI file, but I could be wrong. I don't see how that would help.

If time is more important than quality, the one thing that will definitely decrease the MPEG2 encoding time is to change the quality slider for the MPEG encoding. Normally it is set to the maximum for the DVD Architect templates, but the "Default" template sets it to only 15. The renders go much faster, but the quality is definitely nowhere near as good.

I agree about two levels of rendering not saving time. All the effects processing, rendering, and encoding to MPEG must eventually be done. I can't see how rendering to uncompressed AND then encoding to MPEG can be faster than doing it in one step. My own experiements along these lines have confirmed this: the combined rendering time of two steps is always slightly longer than rendering directly to MPEG in one step.

However, that being said, part of this length of time is due to the Main Concept codec and it's use by Vegas. It is possible that if you use a separate MPEG encoder that runs substantially faster that you may save some time. My guess for this particular project though, since 12 minutes is taking 20 hours to render, that the bulk of the time is being spent handling the complexity of the project rather than the final MPEG encoding. If that's true then speeding up the MPEG encoding probably won't gain much at all.

Modern speedy computers, 2.5GHz and faster, seem to be able to encode MPEG nearly realtime or at most maybe 2x realtime. If this is the case with this project then the MPEG encoding is taking up to 24 minutes of the 20 hours. That means that the rendering part is taking over 19.5 hours. It will still take over 19.5 hours even if rendering directly to uncompressed AVI. 19.5 hours for a 12 minute project? You have a very complex project with lots of effects, compositing, titles, color correction, etc.

Want a faster render? Find a few of the time consuming effects you've added, decide which ones aren't really necessary, and remove them. That will give you a larger rendering speed boost than anything else you could do!

Will at that point "empty" tracks add to render speed efficiency? Would muting that which is outside the complex are assist? Going back and only rendering those portions that are really complex?

Grazie