whats 12V1 and 12V2 in a PSU rating?

[duryodhan]

I am buying a new PSU and was told to get one that has atleast 18A at 12V. I noticed online that the SP500 by Antec has 2 12V lines 12V1 and 12V2 . What does this two stand for? Can I add up the two currents to get actual max. current at 12V?

Also is Antec SP500 better or is Antec NeoHe500 better as a psu?

 

[RallyMaster]

NeoHE 500W is definitely better. It has higher efficiency from what I remember.

 

[Zepper]

Yes, you add the two 12V rails together to get the total (actually it's as noted below - look for the combined +12V rating as the two separate ratings are what can possiby be achieved with one of them driven at a low level of 10% or so with the other split run at max load), but unfortunately with split rail PSUs you often can't use the total Amps available as you can with a single rail PSU (the type I recommend). 12V1 is usually dedicated to powering the CPU(s) while 12V2 carries the rest of the 12V load.

.bh.

 

[Howard]

The max combined power usually can't be found just by adding the nominal max on each rail. Look for a spec for "combined max".

 

[JEDIYoda]

Originally posted by: RallyMaster
NeoHE 500W is definitely better. It has higher efficiency from what I remember.

ER rating is not the only criteria for buying a PSU! duh