Dual Rail power supplies

indianduddawg47

Senior member
Dec 29, 2001
275
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0
Hello,

If a power supply has two 12V lines, are they additive?

For example, let's say I'm comparing two brands, Brand A and Brand B. Brand A and Brand B are identical, except:

Brand A
12V1= 8A
12V2 = 14A

Brand B
12V = 22A

Would there be any difference?

Is there any advantage to getting a dual rail psu over a single rail psu?

My motherboard requires 18A on the 12V line. If I get a PSU with 8A on 12V1 and 14A on 12V2, would that satisfy the 18A requirement?

Thanks,
James
 

Continuity27

Senior member
May 26, 2005
516
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0
Not quite. The thing to remember is each connector is attached to ONE of the two rails. You can only put one connector to the motherboard, so you better make sure one of the two rails matches the motherboard spec.

For example, if you bought a 28A single rail PSU and a dual rail 14A+14A, and the motherboard needed 18A.. ithe dual rail WOULD NOT work.

My dual rail PSU has 18A+18A, which is like a 36A single rail, but remember, if everything you connect is on one rail, you don't have 36A, you have 18A.