Hello, I have gone through some threads here about choosing psus..i found some new things besides Watts....and i found that for those factors in some cases a 600w is better than a 750w.rail voltage is also one factor.would anyone plz explain what are they?a link can be very helpful..i'm not changing my psu soon but want to know what things to see besides watts before buying a gaming rig's power supply.thanks in advance.
PC's use specific voltage and its important that these voltages do no deviate to far from spec. A 5% deviation is allowed for. Your Rail, which are for power, are: molex, pcie, and sata. They all use 12v and 5v. A true sata power connector will also provide 3.3v but I dont know of any device that actually uses it.
Each rail is also supposed to be independant of each other but sometimes testing reveals this is not the case. And not that a single rail PSU is a bad thing in itself, it all depends on what you need or planned for.