What's the real meaning of +12V1 and +12V2?

[Tranq]

I'm currently on an Antec True550 for ATX12V with a 20 pin motherboard connector...i also have a pci-ex graphics card and a 24 pin motherboard so im using multiple adapters which im not very comfortable with...i want to buy the new antec 2.0 truepower 550 watt...it's perfect for me but 19A on +12V1 and +12V2...? what is the meaning of these two rails? what should i consider this to be...i mean 19 amps seems horrible...but im sure there's something im missing...please explain how these two rails work...should i consider this to be 38A???

 

[RealBlackStuff]

That IS a 38A PSU.
The reason they split the +12v, is to supply a stable and steady amount of power to the CPU and perhaps some other vital components via one rail, and have a second rail for equipment such as harddisks, CD/DVD, where the powerdemand is not always the same, and could perhaups cause 'flutters'.