I set my video preview window to Preview(Auto) and minimize Vegas while rendereing. My Dynamic RAM is set to 800 with a Max available of 1024 with 4 threads. Should I lower that?
Jeff

you can lower it to 0 when rendering but if you are using your CPU 100% I don't think you will see any gain as your RAM is keeping your CPU fed with data to work with and you aren't choked by drive write speed.

I will try that. I was just wondering if 100% CPU is OK and if not is there a way to lower it so I have some reserve for other things? I like to surf the web and do email while rendering. Launching outlook and Firefox while rendering sometimes results in Vegas aborting the render. I only have this issue with HDV video which is pretty much all I use now.

Don't multitask while you render. It's not worth the risk of a glitch.
Close unneeded background applications.
100% CPU usage is normal, since it is usually the "bottleneck" in many systems; it must handle the most operations in the least amount of time to attempt to keep up.
If you had a 4 inch pipe with a 1 inch section in the middle, which part would stay 100% full all the time?
Get another computer for your routine surfing and playing, or assign the rendering to another machine on the network.

Good plumbing analogy. I am still working on the concept of which direction things flow. The CPU thing was confusing to me because I have read about folks complaining about low CPU usage while mine is pegged. After a few unsuccessful renders I started using my iPhone for internet stuff. I need a new editing computer and keep this one for other tasks. Thanks everyone for the feedback.
Jeff

Actually there's about 0% risk of other operations causing a glitch in a render. It's not a real-time operation like capturing and printing to tape. I regularly use my main workstation for dozens of other tasks while the render is going on and it never causes any problems, other than making the render take a tiny bit longer.

Try setting the process priority of Vegas to "below normal" while rendering and that will allow other programs to run unimpeded. Vegas will simply and politely step aside, lowering it's CPU usage while other things run. However, since the render will still probably be the most CPU intensive task running, the render probably won't be slowed down much at all.

Actually there's about 0% risk of other operations causing a glitch in a render.

I guess it depends on the system resources available and threads. On my oldest single core desktop, I can't open my browser during an audio render without it causing a glitch in the output. Last time I opened my email during a video render (some years ago) it froze a 20-hour render in its tracks.

On my newer core duo laptop, however, I can merrily surf the web, even compose a Word document with both cores pegged at 100% while rendering. However, if it's something important or going to be a lengthy render, I assign it to another computer on the network and go on about my business.

AVC render from yesterday. 3ghz quadcore. Simple transitions, some audio work, and heavy grading with Bullet.

CPU Meter:
http://i224.photobucket.com/albums/dd173/brizzad79/AVCRender.png

Kelly, I gave that a try. I had Vegas set at a high process priority so I lowered it. Now the CPU usage bops around between 60 and 100%. My page file is still at 1.8GB, however I have outlook and firefox running. Thanks for the suggestion, I am not too concerned with a slower render if I can safely work on other things.
Jeff