Is there latency? Yes.

No PC is infinitely powerful. There will always be a point
if you add enough effects where realtime preview is
impossible. I'll tell you my experience though:

I have my preview window at 720x480 on my main monitor.

If you play a DV track with no effects, you should see no
latency except for the occasional hiccup (especially if you
pan or zoom the track view)

If you add a transition, the preview drops to 8fps during
the transition. I then switch to draft mode and the
transition is smooth (21fps).

In draft mode I can add HSL, contrast, quick blur, and
invert filters which bring my frame rate down to 10fps (7-
8fps during transitions)

At this point, bring up your task manager and try
zooming/panning the interface while you are playing your
video. You'll see that your second processor is almost
fully utilized to keep your interface responsive. My
framerate still drops, but the audio is solid. Switch to
the processes tab in Task manager and right click on
Vegas.exe. Change the affinity so Vegas can't use the
second processor and repeat the zoom/pan experiment. On my
system, the audio breaks up and the framerate drops. Now
you can see the enormous benefit that you can get from dual
processors if you are the type that really pushes your
software. After this experiment, you'll be very happy you
went for dual ;)

(okay now fix the affinity setting so vegas can use dual!)

Adding the wave effect will begin to slow down the frame-
rate to 6-7fps. Switching to preview mode at this point
yields 1-2fps.

It turns out the HSL plugin is the hardest on the cpu of
the bunch that I'm testing. If I turn that off I can get
almost 15fps in draft mode. Using just the contrast and
quickblur gives me near realtime playback.

The question is how is too much latency?
For me editing at 10fps and above is okay. Less than that
is hard to deal with.

I'm impressed with the performance that Vegas delivers.
I've been using graphics applications for a long time and
the idea of processing 20-30 images (each at 720x480)
through 3-4 filters every second is very satisfying :)

I've also used hardware based editing systems and they have
their strong points. But they are always limited in
usefulness. You have to use the filters that are designed
to work with their hardware to take advantage of real-time
performance. You can only mix a certain number of tracks.
And you have to spend at least $3500 (in addition to the
base PC!) to get anything worth using. And that $3500 is
only good for video editing. I do a lot more on my PC than
Video editing so it is better for me to sink the $$ into a
faster PC which enhances ALL my applications.

You can build a killer dual processing Vegas system for
less than $1500 including the PC the hard drives and the
software. Comparing the performance of this setup to an
Avid system is kind of silly.

Anyone else have some performance numbers to post? I'm
always curious as to how I can make things go faster and
smoother. I'm running on:
ASUS CUV4X-D VIA 694XDP Dual CPU Motherboard
with 2 1Gz PIII's 512RAM
160GB IDE RAID
(4x 40GB WD 7200rpm drives on Promise Ultra100)
Win2k - TNT Geforce 2 MX / Matrox Mill 2

It's great to hear that you get a lot out of a minimal
setup. That's one of the coolest things about Vegas, you
don't need much to do amazing creative stuff.

I also read Tom's hardware all the time and agree that for
most people, dual processors aren't worth the extra cost.
But, if you actually utilize them, then getting two cpu's
is certainly worth the trouble. Actually I don't think
there is any trouble to speak of except for the extra cost
of the motherboard and the second CPU, which isn't that
much. I've never run into any driver/stability issues
using dual motherboards.

Dual processors have obvious benefits to 3d rendering
(3dsmax uses both at 100%) and servers, and to multitasking
(rendering and editing at the same time), but the real
question here is whether Vegas actually does take advantage
of 2 cpu's. And the answer is YES! If you want to keep
Vegas as responsive as possible, dual cpu's will help,
along with a RAID setup if you are using more than a couple
tracks of full size video, and plenty of RAM if you are
using lots of high resolution images.

So while you can get away with one cpu and one hard drive,
the harder you push Vegas the more you'll benefit from dual
cpus and a RAID setup. Let me be clear, I'm not saying that
you can't make the coolest movies on earth without a dual
system and a RAID array, because I believe you CAN!

I encourage anyone with dual cpus to do the experiment I
described in my previous post to prove that there is a
clear benefit. To me, the coolest thing about Vegas is the
interface, and the more responsive it is the more fun I
have editing. And who wants to stop creating just because
your pc is busy rendering your last creation? :)