Intel 5400 Series manual Processor Thermal Characterization Parameter Relationships

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Thermal/Mechanical Reference Design

Table 2-6. Fan Speed Control, TCONTROL and DTS Relationship

Condition

FSC Scheme

 

 

DTS ≤ TCONTROL

FSC can adjust fan speed to maintain DTS ≤ TCONTROL (low acoustic region).

 

 

DTS >TCONTROL

FSC should adjust fan speed to keep TCASE at or below the Thermal Profile

 

specification (increased acoustic region).

 

 

There are many different ways of implementing fan speed control, including FSC based on processor ambient temperature, FSC based on processor Digital Thermal Sensor (DTS) temperature or a combination of the two. If FSC is based only on the processor ambient temperature, low acoustic targets can be achieved under low ambient temperature conditions. However, the acoustics cannot be optimized based on the behavior of the processor temperature. If FSC is based only on the Digital Thermal

Sensor, sustained temperatures above TCONTROL drives fans to maximum RPM. If FSC is based both on ambient and Digital Thermal Sensor, ambient temperature can be used

to scale the fan RPM controlled by the Digital Thermal Sensor. This would result in an optimal acoustic performance. Regardless of which scheme is employed, system designers must ensure that the Thermal Profile specification is met when the processor Digital Thermal Sensor temperature exceeds the TCONTOL value for a given processor.

2.4.2Processor Thermal Characterization Parameter Relationships

The idea of a “thermal characterization parameter”, Ψ (psi), is a convenient way to characterize the performance needed for the thermal solution and to compare thermal solutions in identical conditions (heating source, local ambient conditions). A thermal characterization parameter is convenient in that it is calculated using total package power, whereas actual thermal resistance, θ (theta), is calculated using actual power dissipated between two points. Measuring actual power dissipated into the heatsink is difficult, since some of the power is dissipated via heat transfer into the socket and board. Be aware, however, of the limitations of lumped parameters such as Ψ when it comes to a real design. Heat transfer is a three-dimensional phenomenon that can rarely be accurately and easily modeled by lump values.

The case-to-local ambient thermal characterization parameter value (ΨCA) is used as a measure of the thermal performance of the overall thermal solution that is attached to the processor package. It is defined by the following equation, and measured in units of °C/W:

Equation 2-3.ΨCA= (TCASE - TLA) / TDP

Where:

 

ΨCA

= Case-to-local ambient thermal characterization parameter (°C/W).

TCASE

= Processor case temperature (°C).

TLA

= Local ambient temperature in chassis at processor (°C).

TDP

= TDP dissipation (W) (assumes all power dissipates through the

 

integrated heat spreader (IHS)).

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Quad-Core Intel® Xeon® Processor 5400 Series TMDG

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Contents Quad-Core Intel Xeon Processor 5400 Series Thermal/Mechanical Design GuidelinesQuad-Core Intel Xeon Processor 5400 Series Tmdg Contents Figures Preload Test Configuration Tables Reference Revision Description Date Number Initial release of the documentQuad-Core Intel Xeon Processor 5400 Series Tmdg Scope ObjectiveReferences Terms and Descriptions Sheet 1 Definition of TermsTerm Description Terms and Descriptions Sheet 2 TDPIntroduction Processor Mechanical Parameters Table Mechanical RequirementsProcessor Mechanical Parameters Parameter Minimum Maximum UnitQuad-Core Intel Xeon Processor 5400 Series Package Thermal/Mechanical Reference Design Thermal/Mechanical Reference Design Thermal/Mechanical Reference Design Quad-Core Intel Xeon Processor 5400 Series Considerations Processor Thermal Parameters and Features Thermal Control Circuit and TDPDigital Thermal Sensor Multiple Core Special Considerations Platform Environmental Control Interface PeciMultiple Digital Thermal Sensor Operation Heatpipe Orientation for Multiple Core Processors Thermal Monitor for Multiple Core ProductsPROCHOT#, THERMTRIP#, and FORCEPR# Processor Input Processor OutputProcessor Core Geometric Center Dimensions Feature DimensionThermal Profile Equation 2-1.y = ax + bTcontrol Definition Equation 2-2.TCONTROL= -TOFFSETTcontrol and Thermal Profile Interaction Thermal Profile B Performance Targets Thermal/Mechanical Reference Design Thermal/Mechanical Reference Design 2U+ CEK, Thermal Profile a Parameter Maximum Unit1U CEK, Thermal Profile B Sea-Level Fan Fail Guidelines1U Alternative Heatsink Characterizing Cooling Solution Performance Requirements Fan Speed ControlEquation 2-3.ΨCA= Tcase TLA / TDP Processor Thermal Characterization Parameter RelationshipsFan Speed Control, Tcontrol and DTS Relationship Condition FSC SchemeExample Equation 2-4.ΨCA= ΨCS + ΨSAEquation 2-5.ΨCA= Tcase TLA / TDP = 68 45 / 85 = 0.27 C/W Chassis Thermal Design ConsiderationsChassis Thermal Design Capabilities and Improvements Equation 2-6.ΨSA= ΨCA − ΨCS = 0.27 − 0.05 = 0.22 C/WThermal/Mechanical Reference Design Considerations Heatsink SolutionsHeatsink Design Considerations Thermal Interface Material SummaryAssembly Drawing Geometric EnvelopeStructural Considerations of CEK Thermal Solution Performance Characteristics 17 U+ CEK Heatsink Thermal PerformanceThermal Profile Adherence Equation 2-8.y = 0.187*X +=0.187* X +40 Equation 2-9.y = 0.246*X +1UCEKReference Solution Equation 2-10.y = 0.246*X +Components Overview Heatsink with Captive Screws and Standoffs22. Isometric View of the 2U+ CEK Heatsink Thermal Interface Material TIM CEK Heatsink Thermal Mechanical CharacteristicsRecommended Thermal Grease Dispense Weight Processor Minimum Maximum UnitsCEK Spring 24. CEK Spring Isometric ViewThermal/Mechanical Reference Design Fan Specifications Boxed 4-wire PWM/DTS Heatsink Solution Fan Power SupplyDescription Min Typ Max Unit Steady Startup Boxed Processor Contents Systems Considerations Associated with the Active CEKThermal/Mechanical Reference Design Component Overview Figure A-1. Isometric View of the 1U Alternative HeatsinkThermal Profile Adherence Thermal Solution Performance CharactericsEquation A-1. y = 0.331*x + = Processor power value W 1U Alternative Heatsink Thermal/Mechanical Design Table B-1. Mechanical Drawing List Drawing DescriptionFigure B-1 2U CEK Heatsink Sheet 1 Figure B-2 2U CEK Heatsink Sheet 2 Figure B-3 U CEK Heatsink Sheet 3 Figure B-4 2U CEK Heatsink Sheet 4 Figure B-5. CEK Spring Sheet 1 Figure B-6. CEK Spring Sheet 2 Figure B-7. CEK Spring Sheet 3 Mechanical Drawings Mechanical Drawings Mechanical Drawings Mechanical Drawings Mechanical Drawings Mechanical Drawings Figure B-14 U CEK Heatsink Sheet 1 Figure B-15 U CEK Heatsink Sheet 2 Figure B-16 U CEK Heatsink Sheet 3 Figure B-17 U CEK Heatsink Sheet 4 Figure B-18. Active CEK Thermal Solution Volumetric Sheet 1 Figure B-19. Active CEK Thermal Solution Volumetric Sheet 2 Figure B-20. Active CEK Thermal Solution Volumetric Sheet 3 Figure B-21 U Alternative Heatsink 1 Figure B-22 U Alternative Heatsink 2 Figure B-23 U Alternative Heatsink 3 Figure B-24 U Alternative Heatsink 4 Mechanical Drawings Test Preparation OverviewHeatsink Preparation Alternate Heatsink Sample Preparation Figure C-3. Preload Test Configuration Typical Test Equipment Test Procedure ExamplesTime-Zero, Room Temperature Preload Measurement Table C-1. Typical Test EquipmentPreload Degradation under Bake Conditions Heatsink Clip Load Methodology Safety Requirements Safety Requirements Intel Verification Criteria for the Reference Designs Environmental Reliability TestingStructural Reliability Testing Reference Heatsink Thermal VerificationPost-Test Pass Criteria 2.2 Recommended Test SequenceTable E-1 Use Conditions Environment Recommended BIOS/Processor/Memory Test Procedures Material and Recycling RequirementsQuality and Reliability Requirements Intel Enabled Suppliers Supplier InformationAdditional Suppliers For 1U2U Heatsink Alternative CEK Copper Fin Alternative CEK Copper Fin Enabled Suppliers Information 100 Quad-Core Intel Xeon Processor 5400 Series Tmdg
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