Thermal Specifications

6Thermal Specifications

The processor requires a thermal solution to maintain temperatures within its operating limits. Any attempt to operate the processor outside these operating limits may result in permanent damage to the processor and potentially other components within the system. Maintaining the proper thermal environment is key to reliable, long-term system operation.

A complete solution includes both component and system level thermal management features. Component level thermal solutions can include active or passive heatsinks attached to the processor integrated heat spreader (IHS).

This chapter provides data necessary for developing a complete thermal solution. For more information on a thermal solution design, please refer to Chapter 9.

6.1Thermal Specifications

To allow the optimal operation and long-term reliability of Intel processor-based systems, the processor must remain within the minimum and maximum case temperature (TCASE) specifications as defined by the applicable thermal profile. Thermal solutions not designed to provide this level of thermal capability may affect the long-term reliability of the processor and system. For more details on thermal solution design, please refer to the Chapter 9.

The processors implement a methodology for managing processor temperatures which is intended to support acoustic noise reduction through fan speed control and to assure processor reliability. Selection of the appropriate fan speed is based on the relative temperature data reported by the processor’s Digital Temperature Sensor (DTS). The DTS can be read via the Platform Environment Control Interface (PECI) as described in Chapter 7. Alternatively, when PECI is monitored by the PCH, the processor temperature can be read from the PCH via the SMBUS protocol defined in Embedded Controller Support Provided by Platform Controller Hub (PCH). The temperature reported over PECI is always a negative value and represents a delta below the onset of thermal control circuit (TCC) activation, as indicated by PROCHOT# (see Section 6.2, Processor Thermal Features). Systems that implement fan speed control must be designed to use this data. Systems that do not alter the fan speed only need to ensure the case temperature meets the thermal profile specifications.

A single integer change in the PECI value corresponds to approximately 1 °C change in processor temperature. Although each processors DTS is factory calibrated, the accuracy of the DTS will vary from part to part and may also vary slightly with temperature and voltage. In general, each integer change in PECI should equal a temperature change between 0.9 °C and 1.1 °C.

Analysis indicates that real applications are unlikely to cause the processor to consume maximum power dissipation for sustained time periods. Intel recommends that complete thermal solution designs target the Thermal Design Power (TDP), instead of the maximum processor power consumption. The Adaptive Thermal Monitor feature is intended to help protect the processor in the event that an application exceeds the TDP recommendation for a sustained time period. For more details on this feature, refer to

Thermal/Mechanical Specifications and Design Guidelines

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