ct1615 - very nice chart. I added it to my bookmarks for future reference.
Bibanu - That chart shows system power consumption at idle and maximum during the Furmark stress test. During a gaming session a pc system will typically use less power than that shown for FurMark.
The Corsair HX520 is an older model. Four years ago jonnyguru.com did a technical review:http://www.jonnyguru.com/modules.php?name=NDReviews&op=Story&reid=18
ct1615 suggested the psu has one large +12 volt rail that was split rather than three separate rails. I'm pretty sure ct1615 is right. The reviewer at jonnyguru.com could not confirm the psu has three separate rails.
btw - The data label on the psu clearly indicates that the maximum wattage for the +12 volt rails is 480 watts. To determine the amperage one divides the the wattage by 12 volts. 480 watts divided by 12 volts = a total of 40 amps on the +12 volt rail(s).