Motherboard power

[tumpin]

Hi guys,

Im looking at getting a custom power supply made for a mini-itx motherboard to be used as an audio server.

I am told that the 12v rail doesn't need to have much current but I thought that the motherboard / processor are powered from the 12v rail so surely that is where the majority of the current is used?

Can anyone tell me what usually uses the 12v, 5v and 3.3v on the motherboard and devices?

 

[Tealc]

Since the advent of high efficiency DC to DC converters most of the high current draw stuff in PCs these days is powered off the 12v rails. The 5v and 3.3v still have a job to do but not as much as in years gone by. Stuff like USB and motherboard will use the 5v and 3.3v.