[quote]Quote from maxtothemax on December 9, 2011, 22:59
What if I\'m powering, say, an external hard drive off it? Would the extra electricity drive up heat output significantly? [/quote]
If you\'re powering an external hard drive through a RasPi USB port, the +5V current is going through the RasPi PC board from the power input (micro USB). There\'s not much voltage drop across the board, though I\'d worry about the voltage drop across the micro USB cable. You also might trip the RasPi\'s resettable fuse... don\'t know what the rating is. So you\'re probably better off providing a more direct power source to your hard drive.
Regarding the RasPi itself, even if the Model B board is only drawing 500 mA by itself, at 5V that\'s still 2.5W. I hear that the SoC gets pretty warm when it\'s working hard, e.g., lots of graphics and/or video. It\'s a small package for that much power. As long as there\'s some air flow 2.5W is not a problem, but if the case is sealed I\'d worry about it overheating. I tend to be overly cautious about electronics overheating because it can really shorten its lifetime. I\'m probably the only Beagler to put a heat sink on his BeagleBoard\'s SoC.