Speed of hard drive up against HD footage

In my motion graphics class this semester, we will be working with some HD elements to finish up lower thirds, segment titles, etc etc etc in After Effects.

The documentary itself is in HD, consequently so must the graphics be. I recently received a 1 TB hard drive as a gift, but the problem is, it's a MyBook home edition. It only comes with a USB 2.0 port. For the LIFE of me I cannot figure out WHY it only has that, but I am satisfied because it holds so much.

My teacher today told me that USB 2.0 will not be fast enough to handle all of the HD workload going in and out of the drive. Since i will need to work directly off of the drive, speed is important.

Question - Is USB 2.0 *really* too slow to handle a 30 fps, 720p composition? Any way to make it work?