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Hi Tom,

The -12V and -5V lines aren't very critical because they are used to power only the serial and parallel ports of the motherboard, but I'm not sure which powers which.

If you want to do some reading on the subject, here's a few links for you, to good articles about PSUs in general...

http://www.firingsquad.com/guides/power_supply/

http://www.ocworkbench.com/articles/psu/psup1.htm

http://www.amd.com/us-en/Processors/ProductInformation/0,,30_118_756_759^1039^1053,00.html

http://www.amd.com/us-en/Processors/DevelopWithAMD/0,,30_2252_869_1039^4038,00.html


Next time you go shopping for a PSU keep these facts in mind:

The +12V line is used to power all the motors of your computer, like the Hard Drive motors, CD, and/or DVD spindles, the floppy spindle, all the fan motors, and any 'case lighting' that you may have installed, and so on.

On all recent mobos, this line is ALSO being used to power the DC-DC converters, which in turn feed your CPU.
And if your CPU can't get enough 'juice', then nothing will run.
So its very important to have good amperage in that +12v line.

If you have two hard drives (or are planning to have two in the future), or have a CD-RW, plus a CD-ROM, you must have a strong +12v line (an absolute minimum of 15A, and preferably more), in your PSU.

The +3.3V line is used to power your RAM, expansion cards and so on.
Just remember that your Video card IS... you guessed it... an 'expansion card', just like any PCI cards you may have in there.
Some vid cards dont operate on 3.3v, but the motherboard will derive the 1.5 volts needed by the newer video cards from that same 3.3V line.
So its important to have very good Amp numbers in that line.

+5V line. This line is used to power the logic circuits of all the drives of your system. That includes floppy, CD-rom, CD-RW, DVD-RW, hard disk, motherboard circuits and more. Many older motherboards use that +5v line to supply the DC-DC converter to the CPU instead of the 12V line, but that isn't common today.

+5V SB This is the "StandBy" line. It powers part of your PC even if its turned off. The only way to remove that voltage is to unplug the PC. If you want to prepare your PC to be turned on from the keyboard, or you want it turned on at a certain time of the day by itself, you must have at least 2A on that line. Most ATX PSU die just because that +5v 'standby' line blows out.

-12V and -5V lines aren't very critical because they are used to power only the serial and parallel ports of the motherboard.