Intel Q9400S Design Guidelines - Page 14

Introduction

14

Thermal and Mechanical Design Guidelines

1.3

Definition of Terms

Term

Description

ACPI

Advanced Configuration and Power Interface.

BTX

Balanced Technology Extended

Bypass

Bypass is the area between a passive heatsink and any object that can act

to form a duct. For this example, it can be expressed as a dimension away

from the outside dimension of the fins to the nearest surface.

DTS

Digital Thermal Sensor: Processor die sensor temperature defined as an

offset from the onset of PROCHOT#.

FSC

Fan Speed Control: Thermal solution that includes a variable fan speed

which is driven by a PWM signal and uses the digital thermal sensor as a

reference to change the duty cycle of the PWM signal.

Health Monitor

Component

Any standalone or integrated component that is capable of reading the

processor temperature and providing the PWM signal to the 4 pin fan

header.

IHS

Integrated Heat Spreader: a thermally conductive lid integrated into a

processor package to improve heat transfer to a thermal solution through

heat spreading.

LGA775 Socket

The surface mount socket designed to accept the processors in the 775–

Land LGA package.

P

MAX

The maximum power dissipated by a semiconductor component.

PWM

Pulse width modulation is a method of controlling a variable speed fan. The

enabled 4 wire fans use the PWM duty cycle % from the fan speed

controller to modulate the fan speed.

T

A

The measured ambient temperature locally surrounding the processor. The

ambient temperature should be measured just upstream of a passive

heatsink or at the fan inlet for an active heatsink.

T

C

The case temperature of the processor, measured at the geometric center

of the topside of the IHS.

TCC

Thermal Control Circuit: Thermal Monitor uses the TCC to reduce die

temperature by lowering effective processor frequency when the die

temperature has exceeded its operating limits.

T

C-MAX

The maximum case temperature as specified in a component specification.

T

CONTROL

T

CONTROL

is the specification limit for use with the digital thermal sensor.

T

CONTROL_BASE

Constant from the processor datasheet that is added to the T

CONTROL_OFFSET

that results in the value for

T

CONTROL

T

CONTROL_OFFSET

Value read by the BIOS from a processor MSR and added to the

T

CONTROL_BASE

that results in the value for

T

CONTROL

T

DIODE

Temperature reported from the on-die thermal diode.

TDP

Thermal Design Power: A power dissipation target based on worst-case

applications. Thermal solutions should be designed to dissipate the thermal

design power.

T

E

The ambient air temperature external to a system chassis. This

temperature is usually measured at the chassis air inlets.

Section	Page
1 Introduction	11
1.1 Document Goals and Scope	11
1.1.1 Importance of Thermal Management	11
1.1.2 Document Goals	11
1.1.3 Document Scope	12
1.2 References	13
1.3 Definition of Terms	14
2 Processor Thermal/Mechanical Information	17
2.1 Mechanical Requirements	17
2.1.1 Processor Package	17
2.1.2 Heatsink Attach	19
2.1.2.1 General Guidelines	19
2.1.2.2 Heatsink Clip Load Requirement	19
2.1.2.3 Additional Guidelines	20
2.2 Thermal Requirements	20
2.2.1 Processor Case Temperature	20
2.2.2 Thermal Profile	21
2.2.3 TCONTROL	23
2.3 Heatsink Design Considerations	24
2.3.1 Heatsink Size	25
2.3.2 Heatsink Mass	25
2.3.3 Package IHS Flatness	26
2.3.4 Thermal Interface Material	26
2.4 System Thermal Solution Considerations	27
2.4.1 Chassis Thermal Design Capabilities	27
2.4.2 Improving Chassis Thermal Performance	27
2.4.3 Summary	28
2.5 System Integration Considerations	28
3 Thermal Metrology	29
3.1 Characterizing Cooling Performance Requirements	29
3.1.1 Example	31
3.2 Processor Thermal Solution Performance Assessment	31
3.3 Local Ambient Temperature Measurement Guidelines	32
3.4 Processor Case Temperature Measurement Guidelines	34
4 Thermal Management Logic and Thermal Monitor Feature	35
4.1 Processor Power Dissipation	35
4.2 Thermal Monitor Implementation	35
4.2.1 PROCHOT# Signal	36
4.2.2 Thermal Control Circuit	36
4.2.2.1 Thermal Monitor	36
4.2.2.2 Thermal Monitor 2 (TM2)	37
4.2.3 Operation and Configuration	38
4.2.4 On-Demand Mode	39
4.2.5 System Considerations	39
4.2.6 Operating System and Application Software Considerations	40
4.2.7 THERMTRIP# Signal	40
4.2.8 Cooling System Failure Warning	40
4.2.9 Digital Thermal Sensor	41
4.2.10 Platform Environmental Control Interface (PECI)	42
5 Intel® Thermal/Mechanical Reference Design Information	43
5.1 ATX Reference Design Requirements	43
5.2 Validation Results for Reference Design	45
5.2.1 Heatsink Performance	45
5.2.2 Acoustics	46
5.2.3 Altitude	47
5.2.4 Reference Heatsink Thermal Validation	47
5.2.5 Fan Performance for Active Heatsink Thermal Solution	48
5.3 Environmental Reliability Testing	49
5.3.1 Structural Reliability Testing	49
5.3.1.1 Random Vibration Test Procedure	49
5.3.1.2 Shock Test Procedure	49
5.3.2 Power Cycling	51
5.3.3 Recommended BIOS/Processor/Memory Test Procedures	51
5.4 Material and Recycling Requirements	51
5.5 Safety Requirements	52
5.6 Geometric Envelope for Intel® Reference ATX Thermal Mechanical Design	52
5.7 Reference Attach Mechanism	53
5.7.1 Structural Design Strategy	53
5.7.2 Mechanical Interface to the Reference Attach Mechanism	54
6 Intel® Quiet System Technology (Intel® QST)	57
6.1 Intel® Quiet System Technology Algorithm	57
6.1.1 Output Weighting Matrix	58
6.1.2 Proportional-Integral-Derivative (PID)	58
6.2 Board and System Implementation of Intel® Quiet System Technology	60
6.3 Intel® QST Configuration and Tuning	62

Intel Q9400S Design Guidelines - Page 14

Definition of Terms - tdp

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