Vegas Video 4 Preview Quality

Archived from groups: rec.video.desktop (More info?)

Ok, can someone else who is well seasoned in Vegas Help me here.
I've done some lengthy full blown projects with Vegas in the last
couple years & I love it!!!
I built a special PC with the best of the best (within reason) just for
my video editing.
BUT
I still can't use Vegas Preview Quality on anything other than Draft.
Sure I can edit with draft mode (going to my offline tv monitor)
But Why even have preview, good & best when they are practially
unusable. They drop so many frames it's like watching a slide show.
I only use them when I pause the movie, switch to best just to see how
sharp my movie actually is or will be when rendered.

I have Pentium 3.0 Ghz 800fsb
1 Gig Corsair Ram
Asus P4P800 Deluxe Mobo
74Gig SATA 10,000 RPM Raptor Drive
(along with 2 other storage drives SATA&PATA)
ATI 9600 AIW Video Card

All I want to know is that is this can't do any better than my old
Duron AMD 800Ghz system. (I hear the preview is all CPU load)
Then what do I need. I understand and accept the fact that frames will
drop and hardware isn't good enough to support say the "Best"
but anything better than draft!
Is there a computer out there that will not drop frames (noticably)
even in "Preview" or "Good" mode???

Anyone Experienced Know?