asus sabertooth x79 bios

Hello, I'm running a pretty stable ASUS Sabertooth X79/i7-3930k system with 10.8.1 I have had a couple of minor issues, firstly when I try to Overclock I will get a failure to overclock in the BIOS before boot up if I push the CPU above 4.2ghz which seems a tad conservative. Secondly, the USB...