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BuildOrBuy News
Bios Spread Spectrum Control:

An Award Bios Setting? Spread Spectrum Control... This "feature" is required for meeting the CE acceptance test. To be CE Listed for acceptance in the EU (European Market)... CE Marking. Suppose to help reduce EMI. Could also reduce system performance, leave it off as stated by M/B Manuals?

According to AMD for Spread Spectrum Clocking - "Spread-Spectrum (SS) clocking means the clock signal is intentionally varied to spread the timing clock energy over a small frequency range. Go to the Bios and make sure this is enabled. Always modulate the spread downward so that the processor never runs above its rated speed."

We suggest trying the setting both ways to determine best System Performance. 

EMI (Electromagnetic Interference):

An electrical disturbance in a system due to natural phenomena, low-frequency waves from electromechanical devices or high-frequency waves (RFI) from chips and other electronic devices. Here in the US, allowable EMI limits are governed by the FCC. For which we have Class B &* Class A certification. Usually, to meet FCC Class B requires a complete system. Ever notice all of that extemporaneous metal in the font of a new PC Case we have to remove when installing those exposed Drive Bay Devices?


US FCC Class A/B - An FCC certification of radiation limits on digital devices. Class A certification - Business use. Class B - Residential use. Class B is more stringent in order to avoid interference with TV and other home reception. For those FCC Class A/B details, see the US Federal Register - Part 15, Subpart B, of the Federal Register (CFR 47, Parts 0-19).

The Federal Register (1994 to present)

UMR EMC LAB EMC Regulations (Electromagnetic Compatibility) - Quote, "The FCC Rules and Regulations, Title 47, Part 15, Subpart B regulates "unintentional radio-frequency devices". Products regulated include any unintentional radiator (device or system) that generates and uses timing pulses at a rate in excess of 9000 pulses (cycles) per second and uses digital techniques. This includes almost every product that employs a microprocessor including workstations, personal computers, point-of-sale terminals, printers, modems, and many electronic games. It is illegal to sell or advertise for sale any products regulated under Part 15, Subpart B until their radiated and conducted emissions have been measured and found to be in compliance." 

Product Compliance Safety Testing - LTG Services

FCC Issues Change Authorization Change "FCC Will No Longer Accept Equipment Authorization Applications For Class B Computers and Peripherals That Can Be Self-Approved"

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Web Development, Gill Boyd & Team - Posted 03/17/2001; Updated 03/30/2003