Acer Aspire M5640 Service Guide for Aspire M1640 / M3640 / M5640 - Page 51

The following table describes the parameters found in this menu: Parameter Description Auto Detect DIMM/PCI CLK Manufacturer CPU frequency Spread Spectrum This option allows you to enable/disable the feature of auto detecting the clock frequency of the installed PCI bus. This item specifies CPU Manufacturer This item specifies CPU frequency When the motherboard's clock generator pulses, the extreme values (spikes) of the pulses create 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 overlooking because even a slight jitter can introduce a temporary boost in clock speed which may just cause your over lock ed processor to lock up. Optio ns Enabled Disabled Intel 266MHz Enabled 45