The settings there, you might need to disable some other setting you have to make it show up.
disabling EPU Power Saving mode might do the trick
Try to poke around. Like I said I have the same board with an updated BIOS.
Best of luck to you.
The setting I'm referring to you can find here:
http://images.anandtech.com/galleries/1229/ASUS%20BIOS%203%20-%20AI%20Tweaker_575px.png
CPU Offside Mode Sign
CPU Voltage
Yeah there's only offset but that's all you really need anyways.
It's important to note that AUTO does not mean 0.000 offset. -0.005 and +0.005 is the closest you'll get to AUTO bios vcore for your multi.
Should only really use AUTO for stock.
A reason why people recommend QUALITY units in the first place.
If you did proper research in the purchasing of your power supply, it will deliver it's rated power at its rated efficiency.