PCTuning fórum

The fact that increased capacity only shows up as combined current on the +12V lines raises an interesting question: Just how separate are the four +12V lines. Some knowledgeable members of the SPCR forums have done some digging, and discovered that in reality there may only be one or two lines. The discussion is specifically about Seasonic's new M12 line and its rebranded twin from Corsair, but given its similarity to the Energy Plus series, many of the points apply equally to both series. Things get quite technical, but the summary is this:

* Lines are only "separate" insofar as they have separate current limiters on each line. The original source is often (but not always) the same.
* The purpose of having multiple rails is to limit the total VA from one line to 240VA, which means a limit of 240VA ÷ 12V = 20A on each line.
* The circuit board does not identify contact points for either +12V3 or +12V4.
* One user has reportedly been able to draw as much as 30~40A from a single cable set, which should certainly have tripped a current limiter if the rails were actually as specified. We were able to perform a similar test on the Energy Plus.