How are temperatures of the Pentium II processor monitored?
Reader: What method is used to monitor the temperature of Pentium II processors? The ‘hardware monitor’ in the BIOS set-up for my motherboard shows ‘N/A’ next to the CPU temperature. Why? I thought that the CPU case would have some kind of internal device for monitoring the temperature. Does it? Computer Doctor: The Pentium II and Pentium III have a built-in temperature monitor, called a thermal diode, which is connected to pins B14 and B15 in the Slot 1 versions. Unfortunately not all motherboards have the requisite circuitry to read these pins, so on many boards they aren’t connected to anything. Check with your motherboard manufacturer to see if your motherboard has the necessary on-board sensor to read this diode. Intel describes a circuit that can be used on boards with or without the appropriate sensor to accurately monitor die temperature. Download and read the “Pentium III processor Thermal Metrology for CPUID 068h family processors” document at http://developer.intel.com/desig
