Intel E1400 - Celeron 2.0GHz 800MHz 512KB Socket 775 Dual-Core CPU User Manual

Legacy Fan Speed Control
112 Thermal and Mechanical Design Guidelines
These are the minimum parameters required to implement acoustic fan speed control.
See Figure 7-40 for an example. There may be vendor specific options that offer
enhanced functionality. See the appropriate vendor datasheet on how to implement
those features.
Figure 7-40. Fan Speed Control
Diode Temperature
(°C)
T
CONTROL
Min Speed
Full Speed
T
LOW
X %
100 %
Diode Temperature
(°C)
T
CONTROL
Min Speed
Full Speed
T
LOW
X %
100 %
E.2.1.1 Temperature to begin fan acceleration
The first item to consider is the value for T
LOW
. The FSC device needs a minimum
temperature to set as the threshold to begin increasing PWM duty cycle to the fan.
The system designer might initially consider a small temperature range (T
CONTROL
–
T
LOW
= T
RANGE
), 5 °C to accelerate the fan. That would delay the fan accelerating for
the longest time after an increase in T
SENSOR
. There are a number of issues that should
be considered with this strategy
There is little granularity in the fan speeds. For each 1 °C of increase in diode
temperature = 20% jump in PWM duty cycle %
Fan speed oscillation as the thermal solution chases the on-die thermal sensor
temperature
Having T
SENSOR
overshoot T
CONTROL
and the thermal profile causing the Thermal
Control Circuit to activate to reduce the temperature.
In extreme cases THERMTRIP# activates and shuts down the processor
The first two cases can create a poor acoustic response for the user. The third case
the user could notice a drop in performance as the thermal control circuit reduces the
power. Figure
7-41 is an example of this situation. The system begins at idle and the
Maxpower program is started at 65% workload.

Intel E1400 - Celeron 2.0GHz 800MHz 512KB Socket 775 Dual-Core CPU Specifications

General

Brand	Intel
Model	E1400 - Celeron 2.0GHz 800MHz 512KB Socket 775 Dual-Core CPU
Category	Computer Hardware
Language	English

Summary

Introduction

1.1 Document Goals and Scope

Outlines the purpose and boundaries of the thermal design guide.

Processor Thermal/Mechanical Information

2.1 Mechanical Requirements

Details physical and mechanical specifications for processor packages and heatsink attachments.

2.2 Thermal Requirements

Defines processor thermal limits, including thermal profile and TCONTROL.

2.3 Heatsink Design Considerations

Discusses key parameters for designing effective heatsinks.

2.4 System Thermal Solution Considerations

Thermal Metrology

3.1 Characterizing Cooling Performance Requirements

Explains thermal characterization parameters (psi) for evaluating cooling solutions.

3.3 Local Ambient Temperature Measurement Guidelines

3.4 Processor Case Temperature Measurement Guidelines

Details procedures for measuring processor case temperature (TC).

Thermal Management Logic and Thermal Monitor Feature

4.2 Thermal Monitor Implementation

Describes the components and functionality of the processor's thermal monitor.

Balanced Technology Extended (BTX) Thermal/Mechanical Design Information

5.1 Overview of the Balanced Technology Extended (BTX) Reference Design

Introduces the BTX reference design and its compliance.

5.2 Environmental Reliability Testing

Details testing for structural reliability, including vibration and shock.

5.4 Safety Requirements

Specifies safety standards for heatsink and attachment assemblies.

5.5 Geometric Envelope for Intel Reference BTX Thermal Module Assembly

5.6 Preload and TMA Stiffness

Discusses preload requirements and stiffness for BTX platforms.

ATX Thermal/Mechanical Design Information

6.1 ATX Reference Design Requirements

Documents requirements for active air-cooled designs with top-mounted fans.

6.2 Validation Results for Reference Design

6.3 Environmental Reliability Testing

6.5 Safety Requirements

6.6 Geometric Envelope for Intel Reference ATX Thermal Mechanical Design

6.7 Reference Attach Mechanism

Details the design strategy for the reference attach mechanism.

Intel® Quiet System Technology (Intel® QST)

7.1 Intel® QST Algorithm

Explains the objective and methodology of the QST algorithm.

7.2 Board and System Implementation of Intel® QST

7.3 Intel® QST Configuration and Tuning

Describes how to configure and tune the QST subsystem.

7.4 Fan Hub Thermistor and Intel® QST

Appendix A LGA775 Socket Heatsink Loading

A.1 LGA775 Socket Heatsink Considerations

Discusses heatsink clip load for mechanical and thermal performance.

A.2 Metric for Heatsink Preload for ATX/uATX Designs Non-Compliant with Intel® Reference Design

A.3 Heatsink Selection Guidelines

Appendix D Case Temperature Reference Metrology

D.1 Objective and Scope

Defines the procedure for attaching thermocouples for TC measurement.

D.2 Supporting Test Equipment

D.3 Thermal Calibration and Controls

D.4 IHS Groove

D.5 Thermocouple Attach Procedure

Provides a step-by-step guide for attaching thermocouples using solder.

D.6 Thermocouple Wire Management