Hi musawi -
If your sig is accurate, you're running an S478 3.4 Prescott & TCCD RAM. The 3.4 will 14X-multi (PRB=1) if your board & BIOS support it (all my Asus' do), & the TCCD usually can run high as the sky, 1:1, w/minimal Vdimm & good timings.
If you don't want to OC, ATM, you might consider using the lower multi & gettting some nice b/w by crankin' the FSB to put you back at 3.4. Usually good for a bit more snap in your system (you MAY need a single Vcore bump using the lower multi, but it's not written-in-stone).
BTW - I wouldn't worry 'bout overvolting a Pressy while OC'ing. You'll probably take out the mobo or PSU before the freakin' Pressy!
Strat