12V rail in smps

[nagaprasanna]

For what all components does the 12V rail in the smps gives power.what about the other rails.does this12 v rail provide power for the proccessor to run?

 

[cjl]

12 provides the power for most of the power hungry components, including the processor, graphics, and hard drives (among other things).

 

[jsc]

Motherboards pull comparatively little 12 volt power and fans do not pull much either.

All 4 fans in my Antec 900 case on LOW use about .5 amp.

That is one way of telling a PSU with an obsolete design - a really high 5 volt output.