I plan to use this WD drive only as a tertiary (and temporary) back-up to my laptop's hard drive when I'm on the road photographing and to the off-site automatic back-up of said laptop. (In my work flow I download all of each day's images to my laptop and then erase my memory cards for the next day.) It's a very good deal for a 1TB portable drive, which has earned high user ratings for reliability, and it's the second one that I have purchased recently. However, I will not rely on it to be the sole back-up due to the sometimes-fickle nature of external drives. I have tested both of my Passport Ultras, and they work as they should.