Intel QX9770 Design Guidelines - Page 34

LGA775 Socket Heatsink Loading

34

Thermal and Mechanical Design Guidelines

Once the processor has sufficiently cooled, and a minimum activation time has

expired, the operating frequency and voltage transition back to the normal system

operating point. Transition of the VID code will occur first, in order to insure proper

operation once the processor reaches its normal operating frequency. Refer to

Figure 9 for an illustration of this ordering.

Refer to the datasheet for further information on Thermal Monitor 2.

Figure 9. Thermal Monitor 2 Frequency and Voltage Ordering

VID

Frequency

Temperature

T

TM2

f

MAX

f

TM2

VID

VID

TM2

PROCHOT#

Time

4.2.4

Operation and Configuration

To maintain compatibility with previous generations of processors, which have no

integrated thermal logic, the Thermal Control Circuit portion of Thermal Monitor is

disabled by default.

During the boot process, the BIOS must enable the Thermal

Control Circuit.

Thermal Monitor must be enabled to ensure proper processor

operation.

The Thermal Control Circuit feature can be configured and monitored in a number of

ways. OEMs are required to enable the Thermal Control Circuit while using various

registers and outputs to monitor the processor thermal status.

The Thermal Control

Circuit is enabled by the BIOS setting a bit in an MSR (model specific register).

Enabling the Thermal Control Circuit allows the processor to attempt to maintain a

safe operating temperature without the need for special software drivers or interrupt

handling routines.

When the Thermal Control Circuit has been enabled, processor

power consumption will be reduced after the thermal sensor detects a high

temperature, i.e. PROCHOT# assertion.

The Thermal Control Circuit and PROCHOT#

transitions to inactive once the temperature has been reduced below the thermal trip

point, although a small time-based hysteresis has been included to prevent multiple

PROCHOT# transitions around the trip point.

External hardware can monitor

Section	Page
1 Introduction	9
1.1 Document Goals and Scope	9
1.1.1 Importance of Thermal Management	9
1.1.2 Document Goals	9
1.1.3 Document Scope	10
1.2 References	11
1.3 Definition of Terms	11
2 Processor Thermal/Mechanical Information	13
2.1 Mechanical Requirements	13
2.1.1 Processor Package	13
2.1.2 Heatsink Attach	15
2.1.2.1 General Guidelines	15
2.1.2.2 The Pump Assembly Clip Load Requirement	15
2.1.2.3 Additional Guidelines	16
2.2 Thermal Requirements	16
2.2.1 Processor Case Temperature	16
2.2.2 Thermal Profile	17
2.2.3 TCONTROL	18
2.3 Heatsink Design Considerations	19
2.3.1 Heatsink Size	20
2.3.2 Package IHS Flatness	20
2.3.3 Thermal Interface Material	21
2.4 System Thermal Solution Considerations	21
2.4.1 Chassis Thermal Design Capabilities	21
2.4.2 Improving Chassis Thermal Performance	21
2.4.3 Summary	22
2.5 System Integration Considerations	22
3 Thermal Metrology	23
3.1 Characterizing Cooling Performance Requirements	23
3.1.1 Example	25
3.2 Processor Thermal Solution Performance Assessment	26
3.3 Local Ambient Temperature Measurement Guidelines	26
3.4 Processor Case Temperature Measurement Guidelines	29
4 Thermal Management Logic and Thermal Monitor Feature	31
4.1 Processor Power Dissipation	31
4.2 Thermal Monitor Implementation	31
4.2.1 PROCHOT# Signal	32
4.2.2 Thermal Control Circuit	32
4.2.3 Thermal Monitor 2	33
4.2.4 Operation and Configuration	34
4.2.5 On-Demand Mode	35
4.2.6 System Considerations	35
4.2.7 Operating System and Application Software Considerations	36
4.2.8 THERMTRIP# Signal	36
4.2.9 Cooling System Failure Warning	36
4.2.10 Digital Thermal Sensor	37
4.2.11 Platform Environmental Control Interface (PECI)	38
5 Intel Thermal/Mechanical Reference Design Information	39
5.1 Validation Results for the ATX Reference Design	39
5.1.1 Heatsink Performance	40
5.1.2 Acoustics	40
5.1.3 Altitude	41
5.1.4 Reference Heatsink Thermal Validation	41
5.1.5 Fan Motor Performance	42
5.1.6 Pump Motor Performance	43
5.2 Environmental Reliability Testing	44
5.2.1 Structural Reliability Testing	44
5.2.1.1 Random Vibration Test Procedure	44
5.2.1.2 Shock Test Procedure	45
5.2.2 Power Cycling	46
5.2.3 Reliability Testing	46
5.2.3.1 Tubing Material Selection	48
5.2.3.2 Reservoir Sizing	48
5.2.3.3 Reliability Test Results	50
5.2.4 Recommended BIOS/CPU/Memory Test Procedures	51
5.3 Material and Recycling Requirements	52
5.4 Safety Requirements	52
5.5 Geometric Envelope for Intel Reference ATX Thermal Mechanical Design	52
5.6 Reference Attach Mechanism	54
5.7 Socket and Voltage Regulation Cooling Strategy	55
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 & Tuning	62

Intel QX9770 Design Guidelines - Page 34

Operation and Configuration, Thermal Monitor 2 Frequency and Voltage Ordering

Page 34 highlights