[Mr T]

Seems like someone was quicker than me...anyway here's my humble opinion:

"you seem to be the resident authority"

I wouldn't say that but...say it again?...
just kidding.


"When I try to advance in the play window it takes about a second per frame (if I'm zoomed in to the point where I can actually see the frames and what's happening in them). I'm wondering if this is because I have only one hard drive. (?)"

I don't really get your point...assuming that what you call the "play window" is the edit window, when you say "it takes about a second per frame" I hope you're not talking about the Video track...If you've read my posts on the subject, you're probably not, since I've said many times that this track is useless and known to slow processing in a drastic way. Use only the movie window, hide that stupid video track.

"My system is a G4 733, Quicksilver, with a 40g ata, 7200 rpm. I'm assuming (although I know how dangerous assumptions can be) that reading video and audio from the same drive is choking my system. I have my buffer size set as high as possible, and I have about 400meg of ram allocated to PTLE use. So it appears I've got my system at its highest possible performance".

It's not so much that it's choking your system...it's more a matter of drive access. When using the same drive for audio and video, your drive will quickly get fragmented thus giving you a crappy picture and slowing down of the general processing (audio+video). Also, your G4 will have to process both video and audio from the same drive which will be difficult given the IDE access speed.

"Do you feel it would increase my performance if I were to install another ata drive and dedicate it to video only? I've searched until my eyes hurt and can find nothing that pertains to ata drives and quicktime - perhaps I missed something in my fatigued state. Any information you can offer would be greatly appreciated".

Indeed, having dedicated-separated drives for audio and video will definitly help but that won't be enough. It also depends on what picture resolution you're using. I'm using iMovie to capture the movies delivered on DV. I choose the optimal setting in iMovie (full resolution or something like that...the highest setting). Then I open the resulting file in QT, resize the window (this is very important since a huge window will really slow down processing in PT and since you won't be able to resize the movie window once the movie is imported in PT->choose a size that allow you to work properly without the picture being too huge) and then export using Cinepack codec.
Let's be clear, the result in PT is not a full screen-great looking picture but I don't care, all I need is a reliable movie=>no sync problem ("sliding frames"), enough quality to be able to edit FXs or music...
Just in case you'll be considering SCSI, I've tried using SCSI drives along with Adaptec Ultrawide II card but got many "PCI too busy" messages, so I stick with IDE. Just my personnal experience, others will tell you SCSI works great.
One last advice: make sure to ask the people delivering the movie to put some black before the movie's starting point and after the movie's ending point. This will avoid a freezing picture at the end of the program (= hard to be sure where it really ends) and you'll also be sure where it starts...
Hope that helps.