I realize this might be a well talked about topic, What I want to know is, while using the iMac as a display for a MBP via Thunderbolt cable, does the harddrive in the iMac become accessible to the MBP as an external drive? Is it possible to do this with a partition? What else remains active in the iMac? From a cursory search I read that the CPU will remain active which I assume takes stress off the MBP? Can someone break down the whole set up for me?