Originally Posted By: iMacsoontobe
One of the "negatives" with the self powered seems to be needing 2 USB ports instead of one? That was according to the reviews on Amazon.
I see, it's the two power plug kind. From the reviews it seems that the Macs, even the MacBook Air can run with just one cable plugged in though. I have portable external HDs with the dual cable. They work fine on my Macs with one cable. Usually it's Windows laptops that need the extra power from the second port connection. If you're not going to be using it that much and can get by with taking up two ports if needed for the times that you have it plugged in, the price is great. I doubt you'll need two though with that iMac.