I have seen the same problem with editing HD files. (see my recent post pd9 and wtv files).

I have found that very often a re-render without any editing will help, and you can work much more smoothly and quickly with the re-rendered file. It's as if the re-render 'cleans up' the clip for use in PD9. It is best to 'uncheck' SVRT to make sure the clip is fully rendered in this situation.

As far as memory usage, I also have a 64 bit system and have never seen total system memory use go above about 2.2GB, even with 12GB of memory installed. Memory use seems to be little affected by long or short clips. I see the same reliance on disk access, rather than loading the entire file in to memory.

However, with a 'clean' video, I find PD9 responsive, even with the disk access. That delay when clicking different parts of the timeline you mentioned is usually less than a second, and not more than about a second and a half if PD9 is handling the clip properly. (Even for clips of similar size to yours ~ 5GB or more)

Perhaps an SSD would help more, once you have that cleaned up video that PD9 can handle. The SSD would not help PD9 if it can't navigate the clip properly in the first place.

I do not use any shadow file, and find performance is just as good with or without for my system.

I seems as if the memory is used for very complex projects, but for one or a few clips the memory resource is not challenged much.

Hopefully the re-render helps for you.

Ken, I was reading your earlier post when I received your reply. Actually the file I am having so much trouble is, like yours, a WTV file. And ,again like you, I've had a better experience with other format HD files - the time taken to move to a new point on the timeline is much less.

I wonder why the WTV format is so problematic? (Interestingly, in the timeline PD identifies the file as a m2ts file.) To its credit PD8 was among the first to be able to handle correctly the WTV produced by Windows Media Center so the programmers have a good understanding of the format.)

Anyway this issue is nuisance because one of my prime uses for PD is to edit out bits from TV recordings created by WMC. Having to render first and then edit and render again negates the excellent speed advantage PD9 has.

Thanks for the comment.

It is helpful for me, since I was thinking a remote possibility was an erratic hauppauge 1600 capture card.

Assuming you have different capture hardware than that, the common theme is PD9 and how it handles WTV files.

Doing the WTV import and then one re-render is a pain to get to a 'clean' clip, but it is one of the least painful options available. There are other software options available too of course, but WMC is included with Win 7 and easy to use. And as you say, at least PD9 actually deals with WTV files, at least part way.

Ken