This is from the Sony product page inregards to The Vegas Pro 8 Workflow

Real-Time Playback and Nondestructive Editing
Playback and edit video effects, transitions and composites on-the-fly without rendering while viewing each change instantly on external monitors in real-time. Vegas software takes advantage of the PC's processing power by caching complex processes or effects directly to RAM for smooth frame-rate playback and previews.

I'm still using version 7d and the preview window is stuttering even with a few small amount of fx and levels on tracks. I'm getting about 7-12 frames a second.
Does V8 fix this problem?
If i go Quad core will this help real-time palyback?
Or is this problem still the same in V8.

Cheers
Simon

Have you tried doing RAM renders on specific sequences?
Have you tried looping the sequence and letting it play a few times?
Either of these does it for me with a RAM render being the quicker of the two.

I just tried a quick test (cross blur between 2 clips with one media FX (NewBlue Halovision) per clip) on 7.0e and 8.0b.
Both took 5 loops of the cross blur transition segment before they hit 29.97 fps.
Normal playback was full framerate but, once the FX was added, it dropped to between 15 & 20 fps.
BTW, this is on a QX6700 quad core.

Thanks Mike,
Yep i know that trick of letting it loop a few times but what a slow procces, oh well i wonder if other NLE'S have the same problem.
One trick that i do is, un-dock my preview window and for some reason this really helps with playback performance.
I just did a test as i write this and with the window un-docked and it set as best full, it took 8 trips around a 1.17 sec clip to get to full frame, 25fps play back and this was wuth a truck driving by as my footage with saturation boost up a bit.

Oh yeah....
Simon

Other NLE's handle this differently, whether it's extreme optimization to requiring pre-renders for changes to the footage, to pre-rendering. Not to mention those that just have high priced hardware that drive full framerate realtime previews.

There's a difference between realtime previews and full framerate realtime previews.

Shift+B Ram Renders are the best way when you're doing work, ( then it just renders the selection region to RAM and you can view it at full framerate ( assuming you have a lot of FX otherwise you should be getting full framerate on just a simple clip w/o FX ) Lowering your preview settings will help with this too. In intense sections of super heavy composites ( 20 plus layers, 3D planar compositing etc... ) i just kick it down to draft so i can see the motion and then pop it back up and RAM Render when I'm done and review how it looks just to make sure it's right.

Dave