I'm building a gaming rig and I heard that PSU play a major role. I've been researching I heard that 500-550 watts is good for gaming, but I'm not sure (due to many opinion and info) , and I don't really know how to use the 'PSU Calculator' , so I was wondering if someone could help me on this. This is my spec for my desktop (http://pcpartpicker.com/p/YCLcyc). Thanks in advance.