What is the -12v rail on a psu?

[demisor]

The title says it all, is it important to look at? if so what is sufficient? I'm asking because i RMA'd my psu and it has the same problem (a high pitch electricity, squealing noise). I heard it could be from the motherboard but I put off C1E, EIST and C3/C6, as suggested, no result.

This is the psu i have; http://www.mindfactory.de/product_info.php/info/p808837_750-Watt-Corsair-CX-Series-Non-Modular-80--Bronze.html

This is what i'd like to exchange it for; http://www.mindfactory.de/product_info.php/info/p808903_750-Watt-Fortron-Raider-Non-Modular-80--Bronze.html

There's a 0.5v difference on the -12v rail, that's why im asking.

Thanks

 

[ksham]

It's deprecated. I believe there were PCI that used -12V rail. Not used anymore.

 

[demisor]

Thanks for the reply, i wont worry about it then!

 

[ksham]

You're welcome.