Are dual 12v required now?

ToiletDuck · May 10, 2006

I don't understand the dual 12v thing. My system I just shipped out had a 430watt antec true power with one 12v and it ran a dual opteron with a 9700pro. So why do I need a dual 12v?

I've ordered and my opteron 165 and DFI board are in the mail along with the memory and the nVidia 7900Gt. Does that require a dual 12v or can I just find me a PSU with a single 12V and high amps?

Most 12v's I find within my pricerange are anywhere from 18-22amps but a single 12v is like 30-36A. Am I going to be using the other wire?

Martel · May 10, 2006

jiggamanjb said:
Dual +12V Rails: Most PS’s today supply all of their +12V amperage through one rail, just like almost every PS manufacturer supplies their +3.3V and +5V through one rail each. However some forward thinking manufacture’s are supplying their +12V amperage through more than one rail, the most common today for PC’s is to use two +12V rails or dual rails. The new ATX12 V2.0 spec. also requires dual (or more) +12V rails.

Why more than one +12V rail? Electrical isolation for noise and improved voltage regulation. Some devices, usually electromechanical ones having motors, produce noise spikes & voltage fluxuations, these can include pumps, compressors, fans, drives, lights (when turned on & off) and probably TEC’s & Peltiers. By putting these “noisy” devices, that often turn on & off, or at least often change their power (amperage) demands, on a separate rail we isolate them from the MoBo, CPU, Video Card(s) and the other electronic components that are sensitive to noise & sudden changes in voltage. This is a good thing! ATX12 V2.0 is the future.

found here

Check out the stickies, most if not all of what you will want to know is in there.

Fronic · May 10, 2006

Martel said:
found here

Check out the stickies, most if not all of what you will want to know is in there.

Except due to seperate regulators they do not share that amperage and adding it together will do you no good. Even though your "combined" amperage is adequate your PSU might still be underpowered for your hardware.

Dual 12v lines were an Intel requirement in the ATX2.0 spec. They later dropped this requirement, although never officially. Due to the extreme demands from todays GPUs you need adequate 12v amperage. Most mid budget dual 12v aren't able to provide this. Go with single unless you can afford a tri/quad with a 12v line directly to your video card.

Are dual 12v required now?

ToiletDuck

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Martel

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Fronic

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