it will take awhile for sure - Ive imported 100s of thousands of targas into vegas and there are some tricks to speed things up.

1. in windows 2000 and XP (maybe windows in general - but it was much faster in nt4) a lot of files in one directory can really slow you system - even AFTER optimizing windows for such situations (turn off ALL pre-reading of the files and indexing, etc) ..
I notice this once you get to about 25,000-30,000 targas ..
So it helps to keep each directory to less than this instead of say 160,000 files in one directory .... OR
keep them all in the root - it really seem to make a diff. no idea why .. but often projects are transported from one system to another on drives this way and it seem to make things go quicker ..

Vegas works quicker reading these dir. in smaller amounts also of course ..

Now if your external drives/projects are coming from comp. after cgi and effects and etc , most of the time the project is broken down into shots/scenes anyway and you will have 100's or 1000's of sub directories ..(I'm talking full length films) . So its less an issue or none at all.


2. you can frame serve massive quantities of targas into vegas in a few seconds flat and generally this is what I will do almost all the time .. Since also you can do better resizing this way and change speed - you can kill two or more birds with one stone this way ..
It is to bad vegas does not take directly avisynth and virtualdubmod frame served files as does many other applications now (even some very high end ones have added this in recent times) , you have to use vfapi as "in-between".. but its still faster.. OR

Use vegas to frame serve to Vegas - vegas 4 even and just leave it running with all the targas loaded .. I often have 6-10 or more vegas going at once and frame serving to a master vegas .. they are not really all running at once - only when required (turn mem to 0 in those though so they do not reserve memory that is not required and turn off preview in those also)