i think you are misguided by those so called psu calculators. your cpu & gpu will take atleast 99% of its required wattage from +12v rail. and that delta unit has 540W/45A in its +12v rail. your cpu+gpu will take nearly 500w under load. operating a psu under its max capability is not a wise decision,specially when you have expensive components on it. it is always recommended to keep atleast 100w headroom and for Sli this range even bigger. its why i recommended atleast 750w.....
Last edited by @nonymous™; January 31st, 2012 at 23:11.