I had tried to connect my 4 year old portable EHD to my 722 before I upgraded to the Hopper and it wouldn't recognize the drive because it did not have external power. However, I just tried the same drive on both of my Hoppers and it works perfectly. Has this requirement changed or am I living on borrowed time without an external power supply...? I just copy a significant number of shows to it without a hitch. It sure is more convenient than having to deal with finding available power, especially if you are changing which Hopper it's connected to.