Intel X5365 Design Guide - Page 37

Quad-Core Intel® Xeon® Processor 5300 Series Thermal/Mechanical Design Guidelines (TMDG)

37

Thermal/Mechanical Reference Design

2.3.3

Chassis Thermal Design Considerations

2.3.3.1

Chassis Thermal Design Capabilities and Improvements

One of the critical parameters in thermal design is the local ambient temperature

assumption of the processor. Keeping the external chassis temperature fixed, internal

chassis temperature rise is the only component that can affect the processor local

ambient temperature. Every degree gained at the local ambient temperature directly

translates into a degree relief in the processor case temperature.

Given the thermal targets for the processor, it is extremely important to optimize the

chassis design to minimize the air temperature rise upstream to the processor (T

rise

),

hence minimizing the processor local ambient temperature. Please refer to

T

RISE

Reduction Guidelines for Rack Servers and Workstations

for more details.

The heat generated by components within the chassis must be removed to provide an

adequate operating environment for both the processor and other system components.

Moving air through the chassis brings in air from the external ambient environment and

transports the heat generated by the processor and other system components out of

the system. The number, size and relative position of fans, vents and other heat

generating components determine the chassis thermal performance, and the resulting

ambient temperature around the processor. The size and type (passive or active) of the

thermal solution and the amount of system airflow can be traded off against each other

to meet specific system design constraints. Additional constraints are board layout,

spacing, component placement, and structural considerations that limit the thermal

solution size.

In addition to passive heatsinks, fan heatsinks and system fans, other solutions exist

for cooling integrated circuit devices. For example, ducted blowers, heat pipes and

liquid cooling are all capable of dissipating additional heat. Due to their varying

attributes, each of these solutions may be appropriate for a particular system

implementation.

To develop a reliable, cost-effective thermal solution, thermal characterization and

simulation should be carried out at the entire system level, accounting for the thermal

requirements of each component. In addition, acoustic noise constraints may limit the

size, number, placement, and types of fans that can be used in a particular design.

2.4

Thermal/Mechanical Reference Design

Considerations

2.4.1

Heatsink Solutions

2.4.1.1

Heatsink Design Considerations

To remove the heat from the processor, three basic parameters should be considered:

•

The area of the surface on which the heat transfer takes place -

Without any

enhancements, this is the surface of the processor package IHS. One method used

to improve thermal performance is by attaching a heatsink to the IHS. A heatsink

can increase the effective heat transfer surface area by conducting heat out of the

IHS and into the surrounding air through fins attached to the heatsink base.

•

The conduction path from the heat source to the heatsink fins -

Providing a

direct conduction path from the heat source to the heatsink fins and selecting

materials with higher thermal conductivity typically improves heatsink

performance. The length, thickness, and conductivity of the conduction path from

Section	Page
1 Introduction	9
1.1 Objective	9
1.2 Scope	9
1.3 References	9
1.4 Definition of Terms	10
2 Thermal/Mechanical Reference Design	13
2.1 Mechanical Requirements	13
2.1.1 Processor Mechanical Parameters	13
2.1.2 Quad-Core Intel® Xeon® Processor 5300 Series Package	14
2.1.3 Quad-Core Intel® Xeon® Processor 5300 Series Considerations	18
2.2 Processor Thermal Parameters and Features	18
2.2.1 Thermal Control Circuit and TDP	18
2.2.2 Digital Thermal Sensor	20
2.2.3 Platform Environmental Control Interface (PECI)	20
2.2.4 Multiple Core Special Considerations	21
2.2.5 Thermal Profile	24
2.2.6 TCONTROL Definition	25
2.2.7 Thermal Profile Concepts for the Quad-Core Intel® Xeon® Processor 5300 Series	26
2.2.8 Performance Targets	28
2.3 Characterizing Cooling Solution Performance Requirements	33
2.3.1 Fan Speed Control	33
2.3.2 Processor Thermal Characterization Parameter Relationships	35
2.3.3 Chassis Thermal Design Considerations	37
2.4 Thermal/Mechanical Reference Design Considerations	37
2.4.1 Heatsink Solutions	37
2.4.2 Thermal Interface Material	38
2.4.3 Summary	39
2.4.4 Assembly Overview of the Intel Reference Thermal Mechanical Design	40
2.4.5 Thermal Solution Performance Characteristics	42
2.4.6 Thermal Profile Adherence	43
2.4.7 Components Overview	47
2.4.8 Boxed Active Thermal Solution for the Quad-Core Intel® Xeon® Processor 5300 Series	51
A 1U Alternative Heatsink Thermal/Mechanical Design	55
A.1 Component Overview	55
A.2 Thermal Solution Performance Characteristics	56
A.3 Thermal Profile Adherence	57
B Mechanical Drawings	59
C Heatsink Clip Load Methodology	85
C.1 Overview	85
C.2 Test Preparation	85
C.2.1 Heatsink Preparation	85
C.2.2 Typical Test Equipment	88
C.2.3 Test Procedure Examples	88
C.2.4 Time-Zero, Room Temperature Preload Measurement	88
C.2.5 Preload Degradation under Bake Conditions	89
D Safety Requirements	91
E Quality and Reliability Requirements	93
E.1 Intel Verification Criteria for the Reference Designs	93
E.1.1 Reference Heatsink Thermal Verification	93
E.1.2 Environmental Reliability Testing	93
E.1.3 Material and Recycling Requirements	95
F Enabled Suppliers Information	97
F.1 Supplier Information	97
F.1.1 Intel Enabled Suppliers	97

Intel X5365 Design Guide - Page 37

Chassis Thermal Design Considerations, 2.4 Thermal/Mechanical Reference Design Considerations

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