Hello guys just a quick question, so i have my newest Phenom II X4 955 rig all set up and built and i'm waiting for the Sapphire 5870's to come in stock, my question is: Will a 550W Corsair (Which is what i already have) be enough to power a 5870, an overclocked X4 955, 4GB DDR2 RAM, and obviously one HDD and Optical drive? Obviously the worst thing you can do is skimp out on your PSU so i would like to make sure i'm covered. Any thoughts?