MSI Midas 915GM User Manual page 68

2. The greater the Spread Spectrum value is, the greater the EMI is
reduced, and the system will become less stable. For the most
suitable Spread Spectrum value, please consult your local EMI
regulation.
3. Remember to disable Spread Spectrum if you are overclocking
because even a slight jitter can introduce a temporary boost in
clock speed which may just cause your overclocked processor to
lock up.
This item specifies the clock frequency of the CPU host bus (FSB) for overclocking
purposes.
Chapter 4 - BIOS Setup
4-15