You wouldn't change the "FSB" you would change the core multiplier and yes you can reduce the voltage. This is normally automatic with cool and quiet however you can set up a manual clock rate and lock it in with a handly application called K10stat. I use it for a minor Overclock but like I said, it can lock in lower clocks and voltages.
#1: Phenom II C2 955BE @ 3.6, Antec Kuhler 920, Gigabyte GA-MA790FX-DS5, Asus 5870/V2, ASUS Xonar D2X, 4 x 1gig OCZ2N1066SR2GK @800, Antec Truepower New 750, Arc Midi, Vistax64
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