Contec SPI-8451-LLVA User Manual

Page of 123
8. BIOS Setup 
 
 
 
104 
SPI-8451-LLVA, SPI-8452-LLVA, SPI-8451-LVA 
Frequency / Voltage Control 
 
Figure 8.10. Frequency/Voltage Control 
 
Description Choices 
Spread Spectrum 
When the system clock generator pulses, the extreme values 
of the pulse generate excess EMI.    Enabling pulse spectrum 
spread modulation changes the extreme values from spikes to 
flat curves, thus reducing EMI.    This benefit may in some 
cases be outweighed by problems with timing-critical devices, 
such as a clock-sensitive SCSI device.