The Thermal Monitoring Facilities
Introduction to Thermal Monitoring
The Pentium® 4 processor incorporates three thermal monitoring mechanisms:
The Catastrophic Shutdown Detector stops processor execution (by turning off all internal clocks) when the processor's core temperature rises above a preset limit. It is not programmable and is always enabled.
The hardware-based Automatic Thermal Monitoring facility forces the processor to decrease its performance when the core temperature rises above a preset level.
The Software Controlled Clock Modulation mechanism allows software to decrease processor performance to lower the core temperature.
Thermal Monitor Feature Detection
The Thermal Monitoring facilities are detected by executing a CPUID request ...