MSI 645 Ultra Manual page 65

Chapter 3
Spread Spectrum
When the motherboard clock generator pulses, the extreme values (spikes) of
the pulses creates EMI (Electromagnetic Interference). The Spread Spectrum
function reduces the EMI generated by modulating the pulses so that the
spikes of the pulses are reduced to flatter curves. If you do not have any EMI
problem, leave the setting at Disabled for optimal system stability and
performance. But if you are plagued by EMI, setting to Enabled for EMI
reduction. Remember to disable Spread Spectrum if you are overclocking be-
cause even a slight jitter can introduce a temporary boost in clockspeed which
may just cause your overclocked processor to lock up.
Unused PCI Slot/DIMM Clk
This setting enables you to stop or activate the unused PCI slot & DIMM
clock. Setting options: Stop, Action.
CPU Vcore Adjust (V)
This setting is used to adjust the CPU core voltage (Vcore), making overclocking
possible.
Note: Changing CPU Vcore could result in unstable system;
therefore, it is not recommended to change the default setting for
long-term purpose.
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