How Long to Format a 1 TB External Hard Drive?

New 1 TB External Hard Drive (2.5")

I recently purchased a 1 TB Seagate Expansion 2.5" External Hard Drive (Model STBX1000101) and decided that I wanted to do a complete format. 

Although this unit is specified as being USB 3.0 compatible I was having problems using it with the front-panel USB 3.0 connections on my computer.  I still need to confirm whether the problem is with my computer or with this external hard drive. I plan on researching this situation further in the future.  This Seagate Portable Hard Drive works well when connected to my powered USB 2.0 hub and so for now I will just live with the lower speeds of USB 2.0.

Formatting Time Connected to USB 2.0

With the unit connected to a USB 2.0 port, the formatting of my new 1 TB External Hard Drive took about 6 Hours and 45 Minutes.  This was longer than I expected.  Keep in mind that this is a 2.5" drive and I would guess that it is only rated at 5400 RPM.