I just bought a 1 TB fire wire/ USB 3 drive for extra storage and TM. I have a mid 2010 17" MBP and wanted the fire wire for fast access to free up space on my main HD. Well, everytime the computer sleeps the drives disconnect. I did not have this problem while using the USB 2 on my computer. So I spent the extra money for nothing I guess since I just went back to using the USB 2 port since hopefully that will not disconnect. I wonder why there is a difference in the 2 ports.