Dual 12V vs. Singular 12V line

Hey folks,

Hope all is well.

Long story short: I bought a PSU that has dual 12V lines, but the micro ATX board only requires a singular 12V line to run "On-Board" graphics.

I totally forgot to think about this when I bought the PSU in a hurry. Did I goof?

Thanks in advance.

Note: I live in a country where I do not have much to choose from so I'm lucky to find "decent" computer parts. This is why the PSU is what it is.

1. Motherboard MSI N1996
http://www.specsbox.com/142/msi-n199...ard-specs.html

2. PSU FSP400-60EPN 80 Plus Bronze 400W, Dual 12V at 18Amps (on box), but site says 17Amps. Click on Specs...
http://www.fspgroupusa.com/fsp40060epn80/p/847.html

There is nothing glamorous about this computer. Basic HDD, ODD and On-Board graphics.

Dual rails are usually used for SLI or Crossfire graphics, 2 graphics cards. It's actually a good thing that you have that in case you want to upgrade in the future.

Of course, this is all assuming my memory is not faulty at the moment.


Edit:
"80 plus Bronze" is really good, but 400W is likely too low for a dual graphics card setup.
You maybe could run your onboard graphics and a graphics card with it though, which is good.

You'll be fine though. You won't have to worry unless you want to upgrade in the future.

Actually single Vs dual (or triple or quad) rails is sort of a slight of hand trick. In reality standard PSUs only have one 12 volt rail internally but what they do is split the circuit and current cap each circuit, similar to your home's breaker box, and call it a rail. The idea behind limiting the maximum current per rail has more to do with preventing a 12 volt wire from evaporating and catching it's insulation on fire due to a short. It also allows them to use thinner gauge wire for the 12 volt lines.

The drawback of multiple 12 volt rails is if the PSU designers weren't to careful about which devices (determined via the connectors) are attached to which rail. For instance putting the CPU power on the same rail as the video card PCIe power connector when the rail isn't rated very high, like 14 amps, would be bad since both devices could exceed that limit.

The latest ATX12V PSU spec, 2.3, eliminated the requirement that no 12 volt rail exceed a 20 Amp limit.

Thanks folks.