Am using my Asrock P67 Extreme 6 motherboard auto overclock settings to ran my CPU at 4600mhz,,
I entered 1.35volt in the max vcore voltage tab so the motherboard never feeds more then 1.35volt to the CPU..
My motherboard 48x (4800mhz) overclock settings also works on my system but i haven't fully tested if it 100% stable and what the max CPU temps are at this settings yet..
(I Don't know how different your Asrock Fatality bios is to my Extreme 6,but am guessing they going be pretty much the same)