You don't want to lower voltages. ..unless there's too much heat at stock which there shouldn't be . It's the vcore setting usually ththat handles cpu voltage. It's probably set to offset mode by default though and you will have to change it to manual to properly set a manual static voltage/ghz combo. Using offset to over clock isn't easy really and takes some experience . First get the multi up and keep upping the multiplier .5 at a time until the computer is unstable (fails prime 95 or bsod or freezes etc). Once it's unstable THEN you need to bump the voltage up a bit to allow for stability. You can repeat the process over and over until you hit your thermal limits (62 C on package/cpu and 71 C on the socket )