Advantage & Jobs of "dual +12v output"

I Suggest Never Never Ever Buy Dual Railed PSUs Because They Produce Very Low Amperes Which Can Burn Your CPU Or GPU's I Suggest Buying An Single Rail PSU, As Per Your Requirements I Recommend You "COOLER MASTER GX SERIES 550W RS-550-ACAA-E3" It Has SLI & CrossFireX Certification & Can Produce 660W At 85% Efficiency !   !, I Recommend Please Buy That COOLER MASTER PSU Or The eXtreme Power 600 !

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Yes The "COOLER MASTER GX SERIES 550W RS-550-ACAA-E3" Is A Bitttt Expensive Than eXtreme Power 600W But I Do Recommend That   ! I Use 2x GTX 550 Ti On That PSU & Those Are Over-Clocked !   !

That one

With a single +12v rail, there is no need to keep track of which devices are connected to which rail. That makes cable connections easier to manage, and you generally use less cables so you can keep your case neater.

Single or dual rail really isnt important, with a well design PSU you will never notice how many rails it has as they already balanced the connectors across the rails for you. I have covered why it doesnt matter in more detail previously
Single 12V rail or multiple 12V rails? The eternal question answered



This is wrong on a great many levels, dual rail PSUs produce the same amount of current as an equivilent single rail PSU, and low current could never burn out your GPU or CPU, low power causes no damage, only higher power can burn stuff out.

The GX 550W is not a great unit, none of the GX series are. They are all packing suscon caps, and have ripple issues on their minor rails above half load. I would stay clear of them, they cost about as much as a good unit of the same power level so there is no reason to consider them at all. The 550W XFX unit is a good unit, that would definitely be my pick, not because it has single rails but because its a better unit and will last you much longer than the GX 550.

Also, the eXtreme power series is known for being eXtremely poorly labeled, there are many reviews on HW secrets of that series of units, here is a quote from the review of that one in particular, they all tend to end similarly.
http://www.hardwaresecrets.com/article/Cooler-Master-eX...
"Why manufacturers like Cooler Master are still carrying power supplies with fake wattages is a mystery to us. We know that this is a very low-end power supply, but this doesn’t give the manufacturer the right to lie. This unit should be labeled as a 450 W unit and sold for half of its price. Being labeled as a 600 W product and sold for USD 70, it is a complete rip-off."



TL : DR - Go for the XFX, its a much better unit.