Rackbrute is 89 hp. A rackbrute 6U has (2x89)-5 (for power) = 173 useable hp. I own several. Keep in mind that the power on the Rackbrute 3U is the same as the power on the Rackbrute 6U. Arturia recommends no more than 640 mAmps on each bus of the Rackbrute 6U (and 1280mAmps on the single rail of the 3U). I've stuck to that 640mAmps recommendation and so far haven't had any power glitches.