Contec SPI-8451-LVA - Manual (Page 111)

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.