Do latest versions of iMovie & iDVD take advantage of Dual processors?

Question

I've been using iMovie and iDVD a lot on my G4/450GHz but now want to be able to edit widescreen (16:9) video, which I'm told needs a faster processor.
I'm considering upgrading to a G5 1.8 SP (which would provide all the power I need, I think) -- there's still a few of them around. I assume that iMovie/iDVD don't really use the dual processors, or the dual core processor, to advantage. Am I correct?__
(I've only got vague answers from dealers).
In other words, if I get a G5 2.0 DP, wouldn't that be overkill?___
Same for Dual Core models?_____
(I'm not considering the iMac, which would be adequate, because it's too big -- high -- to fit in my desk-wallunit; I haven't seen a flexible stand which would allow adjusting the height of the monitor).

Answer 1

I have a dual 1.25GHz G4 at work. Just fired up
iMovie 5 and applied an effect. While it was
rendering I watched the Activity Monitor. The
processor usage for iMovie never went over 100%,
which is typical of applications that are not taking
advantage of the dual processors. (A so-called
multi-threaded application would have reached 180% or
so with no other apps running.)
Very interesting, Lennart. At first blush, it looks we're getting different results.
Yesterday I checked the processor activity by watching the bars in the "Show CPU Usage" window in Activity Monitor. While rendering a special effect, both processor bars filled almost to the top, which I assumed meant iMovie was using both processors to near capacity.
Today, when I look at the CPU activity reported in the Activity Monitor window, it jumps to 180%, while yours doesn't exceed 100%. Then later, checking it again on another special effect, mine won't exceed 100%.
The difference here seems to be which special effect is working. Some use both processors, apparently, while others don't. "Edge Work" uses both, which I happened to test.
I've tested only a few built-in iMovie functions, but I can't force iMovie itself to move over 100% running its own code. Simultaneously importing a clip and rendering with the KBE, for example, doesn't go over 100%.
So apparently I happened to pick a special effect that used both processors, while iMovie itself does not use both. Both bars move in iMovie, on the other hand, so both processors appear to be working for iMovie. But as one bar goes up the other goes down, and their combined usage never exceeds 100%.
Wish I understood this better.
Karl