Why do I get the message SERIAL PRESENCE DETECT (SPD) device data missing or inconclusive when the system is booting, and what does it mean?

If the system is used for mission critical applications where data integrity is critical, the system should be shut down and (SPD) 100MHz memory installed prior to operation.

 

On each system boot, the processor front side bus speed is automatically selected to support the internal processor speed of the processor. (New systems default to a speed of 100mhz, older systems to 66mhz). If the processor installed supports a front side bus speed of 100MHz and if during the POST (Power On Self Test) boot stage, non-SPD memory is detected or the BIOS can not determine the memory installed meets the SPD 100MHz requirements, the motherboard BIOS will display the following message:

"SERIAL PRESENCE DETECT (SPD) device data missing or inconclusive."
"Properly programmed SPD device data is required for reliable operation."
"Do you wish to attempt to boot at 100MHz bus speed?"
"Y/N [Y] Type [N] to shut down."

Thereafter, while non-SPD memory remains present, the boot screen will display the following message:

"SERIAL PRESENCE DETECT (SPD) device data missing or inconclusive."
"100MHz memory assumed."

Since (SPD) 100MHz memory may not be readily available in some geographies and because some operators may not have critical data integrity requirements, if (SPD) 100MHz memory can not be confirmed during the POST process, the BIOS will provide this information and offer the option to run the system with memory that may not meet the full 100MHz operating requirements.

If the system is used for mission critical applications where data integrity is critical, the system should be shut down and (SPD) 100MHz memory installed prior to operation.

NOTE: Processors with 66-MHz Front Side Bus (FSB) can be paired with either 66-MHz or 100-MHz SDRAM DIMMs. Processors with 100-MHz (FSB) should only be paired with 100-MHz SDRAM DIMMS.

Why do I get the message "serial presence detect (SPD) device data missing or inconclusive.
 

When my system is booting I get the message: "SERIAL PRESENCE DETECT (SPD) device data missing or inconclusive." What does it mean and how can I solve the problem?