Originally Posted by jonnyGURU
Efficiency is the ratio between what's being put out (in DC Watts) and what's being sucked in (AC Watts). It has nothing to do with how rails are distributed.
A power supply only puts out what's demanded of it. So you're not putting out the max capability of each rail. You're only putting out whatever the load on that rail is. And if that load exceeds the capability of that rail, the PSU shuts down. You can have one rail loaded more than another, and that's why the limits of these rails are not additive.
So, there are actually 43.333A available on the 12V rail? I have been meanig to take some measurements as, due to my cable modding, I am running almost everything off one molex lead. I don't have a very demanding system, but I would like to know what the draw actually is.
On a motorcycle, we would sometimes use a shunt to connect a DMM inline with the battery lead to what the ammperage draw is, but I am not sure how to do this with a PSU. I'll have to think on it as, being behind a desk for the last 8 years, my knowlege of these things is slowly being pushed out by other things, lol.