Ok guys i need help to choose my psu because i build my new computer but the psu that i bougth wasn't enough. I have an AMD Phenom X3 720BE, Mobo Asus M2A78-EM, 6gb OCZ Memory DDR-2 800Mhz 2X2 and 1X2, Two Hard Drives 1x500Gb and 1x250Gb, Sony DVD burner,two 120mm case fan coolers, and one Powercolor ATI HD4900. The PSU that i bougth was an Cooler Master of 500W. and wasn't enough. How much watts do i need from a PSU to my system? I was thinking in a Thermaltake Purepower 600w. Thanks in advance.