[Problem] Howto get higher CPU Clock Ratio on ASUS Dual Socket 1366 MBs?

Im looking at dual lga 1366 Asus motherboards and noticed that they have the ability to change the cpu clock ratio, but are limited to 20, even though the cpus are unlocked. Im completely new and was wondering if someone could give me a basic guide to modify a bios to allow the multiplier to get higher.

Edit by Fernando: Thread title customized