Sensor Based Thermal Specification Design Guidance; Sensor Based Specification Overview - Intel BX80605X3440 - Quad Core Xeon X3440 Reference

Sensor Based Thermal Specification Design Guidance

7
Sensor Based Thermal
Specification Design Guidance
The sensor based thermal specification presents opportunities for the system designer
to optimize the acoustics and simplify thermal validation. The sensor based
specification uses the Digital Thermal Sensor information accessed using the PECI
interface.
This chapter will review thermal solution design options, fan speed control design
guidance and implementation options and suggestions on validation both with the TTV
and the live die in a shipping system.
7.1

Sensor Based Specification Overview

Create a thermal specification that meets the following requirements:
• Use Digital Thermal Sensor (DTS) for real-time thermal specification compliance.
• Single point of reference for thermal specification compliance over all operating
conditions.
• Does not require measuring processor power and case temperature during
functional system thermal validation.
• Opportunity for acoustic benefits for DTS values between T
Thermal specifications based on the processor case temperature have some notable
gaps to optimal acoustic design. When the ambient temperature is less than the
maximum design point, the fan spe ed control system (FSC) will over cool the processor.
The FSC has no feedback mechanism to detect this over cooling, this is shown in the
top half of
The sensor based specification will allow the FSC to be operated at the maximum
allowable silicon temperature or T
acoustics for operation above T
Thermal/Mechanical Specifications and Design Guidelines
Figure 7-1.
J
CONTROL
for the measured ambient. This will provide optimal
. See lower half of Figure
and -1.
CONTROL
7-1.
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