12V rails: do they pretty much power everything?

[magellan]

I know HDD's, CD-RW's, DVD-RW's and floppy drives use 5V power, but what else does?
Ditto for 3V power (which I think used to be used to power motherboard chipsets). Does anything use -12V power at all?

 

[redduc900]

Check out the stickies at the top of this forum, and also this article...

Everything you need to know about power supplies
http://www.hardwaresecrets.com/article/Everything-You-Need-to-Know-About-Power-Supplies/181/8

 

[Bobnova]

Short answer: Yes.
-12v really ought to have been removed by now, like -5v was.

 

[NiHaoMike]

Many modern PSUs derive the 5V and 3.3V rails from the 12V rails. Which means the only stuff the 12V rail doesn't run is whatever runs from the 5Vsb rail.

 

[larrymoencurly]

The last time I measured a computer that ran the CPU from +12V, it consume a few amps at +3.3V and fewer amps at +5V. I think the DIMMs are often powered from +5V (10V capacitor in its regulator, meaning the source isn't +12V).

 

[Knufire]

USB supplies power at 5V. Spec is only 500mA per port though.

 

[Bobnova]

Depends, USB3 gets 1.5a.