Intel Q9450 Design Guidelines - Page 47

Intel® Thermal/Mechanical Reference Design Information

Thermal and Mechanical Design Guidelines

47

While the fan hub thermistor helps optimize acoustics at high processor workloads by

adapting the maximum fan speed to support the processor thermal profile, additional

acoustic improvements can be achieved at lower processor workload by using the

T

CONTROL

specifications described in Section

2.2.3. Intel recommendation is to use the

Fan Specification for 4 Wire PWM Controlled Fans

to implement fan speed control

capability based on the digital thermal sensor. Refer to Chapter

6 for further details.

5.2.3

Altitude

The reference heatsink solutions were evaluated at sea level. However, many

companies design products that must function reliably at high altitude, typically

1,500 m [5,000 ft] or more. Air-cooled temperature calculations and measurements at

sea level must be adjusted to take into account altitude effects like variation in air

density and overall heat capacity. This often leads to some degradation in thermal

solution performance compared to what is obtained at sea level, with lower fan

performance and higher surface temperatures. The system designer needs to account

for altitude effects in the overall system thermal design to make sure that the T

C

requirement for the processor is met at the targeted altitude.

5.2.4

Reference Heatsink Thermal Validation

The Intel reference heatsink was validated within the specific boundary conditions

based on the methodology described Section

5.3 , and using a thermal test vehicle.

Testing is done on bench top test boards at ambient lab temperature. In particular, for

the reference heatsink, the Plexiglas* barrier is installed 81.28 mm [3.2 in] above the

motherboard (refer to Section

3.3).

The test results, for a number of samples, are reported in terms of a worst-case mean

+ 3



value for thermal characterization parameter using real processors (based on the

thermal test vehicle correction factors).

Note:

The above 81.28 mm obstruction height that is used for testing complies with the

recommended obstruction height of 88.9 mm for the ATX form factor. However, it

would conflict with systems in strict compliance with the ATX specification which

allows an obstruction as low as 76.2 mm above the motherboard surface in Area A.

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 Q9450 Design Guidelines - Page 47

Altitude, Reference Heatsink Thermal Validation

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