I just got my iPhoto library setup on a LaCie 6TB Thunderbolt drive. The photos have indexed themselves and scanned for Faces. For some reason when I am running iPhoto, it is using 25% CPU and is constantly accessing the HDD when I am not performing any actions in iPhoto. I have left it like this for a couple of hours thinking maybe it was just doing some sort of indexing however, it still does it every time I launch the app. I can't figure out what it is doing. Any ideas? 