That PSU calc is way off...according to it my system should pull close to 500W at full load. According to the Magnum EX it's closer to 200W.
Phenom II 940 Black Edition quad core @ 3.5Ghz
4x2 Gigs Patriot PC2 6400
Cooler Master HAF XB EVO,
Some other stuff,
Even more stuff,
If the automobile had followed the same development cycle as the computer, a Rolls-Royce would today cost $100, get a million miles per gallon, and explode once a year, killing everyone inside. --Robert X. Cringely, InfoWorld magazine