So I currently own a Microsoft surface 2, of the rt variant. I really want to expand memory for photos and videos etc. I have my mind set between two external hard drives: Seagate Expansion 1tb Portable OR the Desktop version. The only difference is that the portable version is a 2.5" disk running off USB power, and the desktop version is a 3.5" standard size hard drive disk running off of an a/c adaptors power. The real question is, with my USB 2.0 hub, will my surface be able to power the portable hard drive? Or would it be safer to buy the hard drive that runs off of an external power source. They are very close in price, so that isn't an issue. I will entertain anyone's $0.02