720×486 at 23.976 fps. I have also been working primarily on external drives. I have almost all of my media files on 4 external hard drives. 3 of these drives are Seagate FreeAgent Desktop External Hard Drives that spin at 7200RPM, and the other is a Western Digital My Book Essential External Hard Drive, of which I cannot find or remember the drive speed, but it has a data transfer rate of up to 480 Mb/sec.
Does this help?
Ryan