Intel QX9770 Design Guidelines - Page 33

Thermal Management Logic and Thermal Monitor Feature

Thermal and Mechanical Design Guidelines

33

Figure 8. Concept for Clocks under Thermal Monitor Control

PROCHOT#

Resultant

internal clock

Normal clock

Internal clock

Duty cycle

control

4.2.3

Thermal Monitor 2

The processor supports an enhanced Thermal Control Circuit. In conjunction with the

existing Thermal Monitor logic, this capability is known as Thermal Monitor 2. This

enhanced TCC provides an efficient means of reducing the power consumption within

the processor and limiting the processor temperature.

When Thermal Monitor 2 is enabled, and a high temperature situation is detected, the

enhanced TCC will be activated. The enhanced TCC causes the processor to adjust its

operating frequency (by dropping the bus-to-core multiplier to its minimum available

value) and input voltage identification (VID) value. This combination of reduced

frequency and VID results in a reduction in processor power consumption.

A processor enabled for Thermal Monitor 2 includes two operating points, each

consisting of a specific operating frequency and voltage. The first operating point

represents the normal operating condition for the processor.

The second operating point consists of both a lower operating frequency and voltage.

When the TCC is activated, the processor automatically transitions to the new

frequency.

This transition occurs very rapidly (on the order of 5 microseconds).

During the frequency transition, the processor is unable to service any bus requests,

all bus traffic is blocked.

Edge-triggered interrupts will be latched and kept pending

until the processor resumes operation at the new frequency.

Once the new operating frequency is engaged, the processor will transition to the new

core operating voltage by issuing a new VID code to the voltage regulator. The

voltage regulator must support VID transitions in order to support Thermal Monitor 2.

During the voltage change, it will be necessary to transition through multiple VID

codes to reach the target operating voltage.

Each step will be one VID table entry

(i.e., 12.5 mV steps).

The processor continues to execute instructions during the

voltage transition. Operation at the lower voltage reduces the power consumption of

the processor, providing a temperature reduction.

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 33

Thermal Monitor 2, Concept for Clocks under Thermal Monitor Control

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