dont forget to check amp rating, some 600 watt psu have less amps then a corsair 430. amperage is more vital in carrying large loads that just rated wattage. i was going to upgrade to a 600 until i realized my 430 corsair has more amps then many 600's. my 7850 under full load and overclocked to 1150 mhz only pulls my 12v voltage down by 0.03 volts.
Yes you should pay attention to what the different rails can put out. Some manufacturers rate their PSU a high total wattage and then stupidly put a ton of amp capacity into one of the unused rails which doesn't help anyone. They should get the "scammer" title hahahaha.
