[SOLVED] What is "Amps on 12 volt rails"?

[Jacob 51]

I've seen a lot of folk mention this on Tom's Hardware. I wanna know what this really means in a PSU.

 

[thx1138v2]

A "rail" is a circuit in the PSU that supplies 12 volts. A volt is a measure of potential on the rail. Some PSU's have multiple circuits for independent 12 volt "rails". "Amps" is short for amperes which is a measure of electrical current.

So "Amps on 12 volt rails" is the maximum current that can be supplied to the computer on 12 Volt circuits, regardless of how many are present.

 

[TerryLaze]

In simple words, the more amps you have on a "rail" , the more and more demanding(on power) components you can put on that channel.
But don't go crazy over that, if you don't use heavy duty stuff you also don't need too much from your PSU.
It's mostly very important for really heavy overclock where everything draws much more power than normaly.

 

[Bob.B]

I've seen a lot of folk mention this on Tom's Hardware. I wanna know what this really means in a PSU.

Think of it like water flowing through a hose.
Volts is the water pressure.
Amps is the amount of water flowing through a hose.

 

[Eximo]

Since no one has mentioned it:

Power supplies are generally rated in total wattage output. Volts * Amps = Watts.

Good power supplies measure their 12V amperage output alone and call the power rating of the PSU. 12 x 36 or so would be your 430W power supplies. Cheaper power supplies will add up 5V, and 3.3V output to reach a total. This is a very old method and doesn't apply well to late model power supplies or computers which basically are 100% 12V devices (and with the new 12VO standard, actually will be in a few years time)