My portable hard drive fell and is now dead so I need to buy a new one. I want to get the Seagate Expansion 1TB External Hard Drive. One model says Portable and the other says Desktop. The desktop model uses a separate power supply and the portable model is powered by the USB. Is there any real difference in terms of safety? For instance, if both of them were to fall on the ground, would both of them break or would the desktop model have a better chance of surviving the fall?