If trying to conserve power, what works best (ie. Turning off leds, using a lower sampling rate, ???
Lowest power draw would be no phantom, no timecode output, display all the way down, lower sample rates, and writing to CF only (the hd will spin down). If you need to be super-current concious, pull the hard drive. On power up the drive always spins up for verification. If you pull it, you save that 5 watts of spin up draw.