Trying to transfer and backup large hard drives. I leave the house, come back, and the transfer has not completed. I have all my system preferences chosen accordingly: no screen saver Energy Saver = prevent computer from going to sleep automatically when display is off I DO have "turn display off after one hour", but nothing else clicked in energy saver, like put hard discs to sleep or enable power nap. Why does the computer stop transferring files? It does look like about one hour of data has transferred. Could "turn display off" be affecting this" thanks!