i have a 925 presler (stock 3.0ghz and voltages are 1.225V-1.312V according to newegg) overclocked to 3.9ghz (260x15). in cpuz voltage shows 1.288 but in the bios it shows as 1.3xx. why are the voltages in the bios and in cpuz different? also i sometimes experience random restarts, but not very often, should i up the voltages to make the system more stable?