R 64-bit Intel® Xeon™ Processor MP with 1 MB L2 Cache Thermal/Mechanical Design Guidelines March 2005 Document Number: 306750-001
R INFORMATION IN THIS DOCUMENT IS PROVIDED IN CONNECTION WITH INTEL® PRODUCTS. NO LICENSE, EXPRESS OR IMPLIED, BY ESTOPPEL OR OTHERWISE, TO ANY INTELLECTUAL PROPERTY RIGHTS IS GRANTED BY THIS DOCUMENT.
R Contents 1 Introduction ....................................................................................................................... 7 1.1 Objective ................................................................................................................ 7 1.2 Scope ..................................................................................................................... 7 1.3 References.........................................................................................
R F Processor Thermal Management Logic and Thermal Monitor Features................... 55 F.1 Thermal Management Logic and Thermal Monitor Feature ................................ 55 F.1.1 Processor Power Dissipation .................................................................. 55 F.1.2 Thermal Monitor Implementation ............................................................ 55 F.1.3 Operation and Configuration................................................................... 57 F.1.
R B-9 B-10 B-11 B-12 B-13 B-14 B-15 B-16 B-17 D-1 D-2 F-1 F-2 F-3 F-4 Measuring Resistance between Thermocouple and IHS .................................... 42 Applying the Adhesive on the Thermocouple Bead............................................. 42 Thermocouple Wire Management in the Groove................................................. 43 Removing Excess Adhesive from the IHS ........................................................... 44 Filling the Groove with Adhesive...........................
R Revision History Revision Number 001 Description • Initial release of the document. Date March 2005 Note: Not all revisions may be published.
R 1 Introduction 1.1 Objective This guide describes the reference thermal/mechanical solution and design parameters required for the 64-bit Intel® Xeon™ processor MP with 1 MB L2 cache. It is also the intent of this document to comprehend and demonstrate the processor cooling solution features and requirements.
R Introduction 1.4 Definition of Terms Term 8 Description Bypass Bypass is the area between a passive heatsink and any object that can act to form a duct. For this example, it can be expressed as a dimension away from the outside dimension of the fins to the nearest surface. FMB Flexible Motherboard Guideline: an estimate of the maximum value of a processor specification over certain time periods.
R 2 Thermal/Mechanical Reference Design 2.1 Mechanical Requirements The mechanical performance of the processor cooling solution satisfies the requirements and volumetric keepouts as described in this section. 2.1.1 Performance Target Table 2-1. Performance Target Table Parameter Minimum Maximum Unit Refer to drawings in Appendix A Volumetric Requirements and Keepouts 1000 g 2.2 lbs 44 222 N 10 50 lbf 44 288 N 10 65 lbf 222 N + 0.
R Thermal/Mechanical Reference Design 2.1.2 Critical Interface Dimensions (CID) The CID drawing illustrates the key interfaces between the package and the thermal/mechanical solution for the processor. Should there be any conflict, this drawing is superseded by the drawing in the processor datasheet. Figure 2-1.
R Thermal/Mechanical Reference Design Figure 2-2. Critical Interface Dimensions (Sheet 2 of 2) 2.2 Thermal Requirements In order to remain within a certain case temperature (TCASE) specification to achieve optimal operation and long-term reliability, the thermal specification methodology, referred to as the thermal profile, is used. The intent of the thermal profile specification is to support acoustic noise reduction through fan speed control and ensure the long-term reliability of the processor.
R Thermal/Mechanical Reference Design Where: y = Processor case temperature, TCASE (°C) x = Processor power consumption (W) a = Case-to-ambient thermal resistance, ΨCA (°C/W) b = Processor local ambient temperature, TLA (°C) Figure 2-3.
R Thermal/Mechanical Reference Design 2.2.2 TCONTROL Definition TCONTROL is a temperature specification based on a temperature reading from the processor’s thermal diode. TCONTROL defines the lower end of the Thermal Profile line for a given processor, and it can be described as a trigger point for fan speed control implementation. The value for TCONTROL is calibrated in manufacturing and configured for each processor individually.
R Thermal/Mechanical Reference Design Thermal Profile between the TCASEMAX@TCONTROL and TCASEMAX points at the corresponding power levels. Refer to Section 2.3.1 for the implementation of the TCONTROL value in support of fan speed control (FSC) design to achieve better acoustic performance. 2.2.3 Performance Targets The Thermal Profile specification for this processor is published in the 64-bit Intel® Xeon™ Processor MP with 1 MB L2 Cache Datasheet.
R Thermal/Mechanical Reference Design Table 2-2. Performance Target Table (Sheet 2 of 2) Parameter Minimum Maximum Unit Notes TCASE_MAX 73 °C In case of conflict, datasheet supercedes TMDG. TCASE_MAX @ Pcontrol_base 50 °C Pcontrol_base = 20 W TLA 40 °C TDP 110 W In case of conflict, datasheet supercedes TMDG. 2.3 Characterizing Cooling Solution Performance Requirements 2.3.
R Thermal/Mechanical Reference Design Table 2-3. Fan Speed Control, TCONTROL and TDIODE Relationship Condition FSC Scheme TDIODE ≤ TCONTROL FSC can adjust fan speed to maintain TDIODE ≤ TCONTROL (low acoustic region). TDIODE > TCONTROL FSC should adjust fan speed to keep TCASE at or below the Thermal Profile specification (increased acoustic region).
R Thermal/Mechanical Reference Design Where: ΨCS = Thermal characterization parameter of the TIM (°C/W). ΨSA = Thermal characterization parameter from heatsink-to-local ambient (°C/W). ΨCS is strongly dependent on the thermal conductivity and thickness of the TIM between the heatsink and IHS. ΨSA is a measure of the thermal characterization parameter from the bottom of the heatsink to the local ambient air. ΨSA is dependent on the heatsink material, thermal conductivity, and geometry.
R Thermal/Mechanical Reference Design ΨCA = (TCASE – TLA) / TDP = (68 – 45) / 85 = 0.27 °C/W To determine the required heatsink performance, a heatsink solution provider would need to determine ΨCS performance for the selected TIM and mechanical load configuration. If the heatsink solution was designed to work with a TIM material performing at ΨCS ≤ 0.05 °C/W, solving for equation 2 from above, the performance of the heatsink would be: ΨSA = ΨCA − ΨCS = 0.27 − 0.05 = 0.
R Thermal/Mechanical Reference 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.
R Thermal/Mechanical Reference Design All thermal interface materials should be sized and positioned on the heatsink base in a way that ensures the entire processor IHS area is covered. It is important to compensate for heatsink-toprocessor attach positional alignment when selecting the proper TIM size. When pre-applied material is used, it is recommended to have a protective application tape over it. This tape must be removed prior to heatsink installation.
R Thermal/Mechanical Reference Design 2.4.4.2 Assembly Drawing Figure 2-8. Exploded View of Cooling Solution Thermal Solution Components 2.4.5 Thermal Solution Performance Characteristics The optimization of the cooling solution heatsink for thermal performance is completed and Figure 2-9 shows the thermal performance and the pressure drop through fins of the heatsink versus the airflow provided.
R Thermal/Mechanical Reference Design Figure 2-9. 2U+ Cooling Solution Heatsink Thermal Performance 0.55 0.80 0.50 0.70 2 0.60 0.40 0.50 0.35 0.40 0.30 0.30 0.25 0.20 Mean Test Ψca = 0.2199 + 1.4415*CFM-1.0496 σ = 0.0086 C/W, non-uniform heat 0.20 0.15 0 10 20 30 40 50 60 70 80 90 ∆P, inch water Ψca, C/W ∆P Test = 5.47e-05CFM + 5.26e-03CFM 0.45 0.10 0.
R Thermal/Mechanical Reference Design 2.4.7 Components Overview 2.4.7.1 Heatsink with Captive Screws and Standoffs The cooling solution reference heatsink uses snapped-fin technology for its design. It consists of a copper base and copper fins with Shin-Etsu* G751 thermal grease as the TIM. The mounting screws and standoffs are also made captive to the heatsink base for ease of handling and assembly as shown in Figure 2-10. Figure 2-10.
R Thermal/Mechanical Reference Design 2.4.7.2 Thermal Interface Material (TIM-2) A TIM must be applied between the package and the heatsink to ensure thermal conduction. The cooling solution reference design uses Shin-Etsu* G751 thermal grease. The recommended grease dispenses weight to ensure full coverage of the processor IHS is given below. For an alternate TIM, full coverage of the entire processor IHS is recommended. Table 2-4.
R Thermal/Mechanical Reference Design Figure 2-11. Hat Spring Isometric View Figure 2-12. Isometric View of Hat Spring Attachment to the Base Board Secondary Primary Primary Secondary Please refer to Appendix A for more detailed mechanical drawings of the hat spring. Also, the baseboard keepout requirements shown in Appendix A must be met to use this hat spring design.
R Thermal/Mechanical Reference Design 26 64-bit Intel® Xeon™ Processor MP with 1 MB L2 Cache Thermal/Mechanical Design Guidelines
R A Mechanical Drawings The mechanical drawings included in this appendix. These drawings refer to the thermal mechanical enabling components for the 64-bit Intel Xeon processor MP with 1 MB L2 cache. Note: Intel reserves the right to make changes and modifications to the design as necessary. Table A-1.
R Mechanical Drawings Figure A-1. 2U Cooling Solution Heatsink (Sheet 1 of 4) Figure A-2.
R Mechanical Drawings Figure A-3. 2U Cooling Solution Heatsink (Sheet 3 of 4) Figure A-4.
R Mechanical Drawings Figure A-5. Cooling Solution Hat Spring (Sheet 1 of 3) Figure A-6.
R Mechanical Drawings Figure A-7.
R Mechanical Drawings Figure A-8.
R Mechanical Drawings Figure A-9.
R Mechanical Drawings Figure A-10. Baseboard Keepout Footprint Definition and Height Restrictions for Enabling Components (Sheet 3 of 5) Figure A-11.
R Mechanical Drawings Figure A-12.
R Mechanical Drawings 36 64-bit Intel® Xeon™ Processor MP with 1 MB L2 Cache Thermal/Mechanical Design Guidelines
R B Testing Methods B.1 Case Measurement Processor cooling performance is determined by measuring the case temperature using a thermocouple and then applying the corresponding correction offset to this measurement. For case temperature measurements, the attach method outlined in this section is recommended for mounting a thermocouple. Special care is required when measuring case temperature (TC) to ensure an accurate temperature measurement. Thermocouples are often used to measure TC.
R Testing Methods B.3 Thermal Calibration and Controls It is recommended that full and routine calibration of temperature measurement equipment be performed before attempting to perform temperature case measurement of processors. Intel recommends checking the meter probe set against known standards. This should be done at 0 ºC (using ice bath or other stable temperature source) and at an elevated temperature, around 80 ºC (using an appropriate temperature source).
R Testing Methods Figure B-2. Groove to Pin Indicator When the processor is installed in the socket, the groove is perpendicular to the socket load lever, and on the opposite side of the lever. Figure B-3. IHS Groove Select a machine shop that is capable of holding drawing specified tolerances. IHS channel geometry is critical for repeatable placement of the thermocouple bead, ensuring precise thermal measurements.
R Testing Methods Figure B-4. Bending Tip of Thermocouple B.6 40 Thermocouple Attachment to the IHS 1. Clean groove with IPA and a lint free cloth removing all residues prior to thermocouple attachment. 2. Place the thermocouple wire inside the groove letting the exposed wire and bead extend about 3.2 mm [0.125 inch] past the end of groove. Secure it with Kapton tape. 3.
R Testing Methods Figure B-5. Securing Thermocouple Wires with Kapton* Tape Figure B-6. Thermocouple Bead Placement Figure B-7.
R Testing Methods Figure B-8. 3D Micromanipulator to Secure Bead Location Figure B-9. Measuring Resistance between Thermocouple and IHS Figure B-10.
R Testing Methods B.7 Curing Process 1. Let the thermocouple attach set in the open-air for at least 1/2 Hr. It is not recommended to use any curing accelerator like Loctite* Accelerator 7452 for this step, as rapid contraction of the adhesive during curing may weaken bead attach on the IHS. 2. Reconfirm electrical connectivity with DMM before removing the micromanipulator. 3. Remove the 3D Arm needle by holding down the processor unit and lifting the arm. 4.
R Testing Methods Figure B-12. Removing Excess Adhesive from the IHS Figure B-13. Filling the Groove with Adhesive When installing the processor into the socket, make sure that the thermocouple wires exit above the load plate. Pinching the thermocouple wires between the load plate and the IHS will likely damage the wires. Note: When thermocouple wires are damaged, the resulting reading may likely be wrong.
R Testing Methods Figure B-14. Thermocouple Wire Management B.9 Local Air Thermocouple Placement For passive heatsinks, two thermocouples will be placed 10 mm upstream of the processor heatsink. The thermocouples will be centered with respect to the height of the heatsink fins and evenly across the width of the heatsink. For active heatsinks, four thermocouples will be placed on the fan inlet. These thermocouples will be mounted between 5 mm and 10 mm above the fan.
R Testing Methods Figure B-16. Local Air Thermocouple Placement for Active Heatsinks (Side View) Figure B-17.
R C Safety Requirements Heatsink and attachment assemblies shall be consistent with the manufacture of units that meet the safety standards: • UL Recognition-approved for flammability at the system level. All mechanical and thermal enabling components must be a minimum UL94V-2 approved. • CSA Certification. All mechanical and thermal enabling components must have CSA certification. • Heatsink fins must meet the test requirements of UL1439 for sharp edges.
R Safety Requirements 48 64-bit Intel® Xeon™ Processor MP with 1 MB L2 Cache Thermal/Mechanical Design Guidelines
R D Quality and Reliability Requirements D.1 Intel Verification Criteria for the Reference Designs D.1.1 Reference Heatsink Thermal Verification The Intel reference heatsinks will be verified within specific boundary conditions based on the methodology described in Appendix B. The test results, for a number of samples, are reported in terms of a worst-case mean + 3σ value for thermal characterization parameter using real processors. D.1.2 Environmental Reliability Testing D.1.2.
R Quality and Reliability Requirements D.1.2.3 Shock Test Procedure Recommended performance requirement for a baseboard: • Quantity: 3 drops for + and – directions in each of 3 perpendicular axes (i.e. total 18 drops). • Profile: 50 G trapezoidal waveform, 11 ms duration, 4.32 m/sec minimum velocity change. • Setup: Mount sample board on test fixture. Figure D-2. Shock Acceleration Curve 60 Accelration (g) 50 40 30 20 10 0 0 2 4 6 8 10 12 Time (Milliseconds) D.1.2.
R Quality and Reliability Requirements D.1.2.6 Recommended BIOS/Processor/Memory Test Procedures This test is to ensure proper operation of the product before and after environmental stresses, with the thermal mechanical enabling components assembled. The test shall be conducted on a fully operational baseboard that has not been exposed to any battery of tests prior to the test being considered.
R Quality and Reliability Requirements 52 64-bit Intel® Xeon™ Processor MP with 1 MB L2 Cache Thermal/Mechanical Design Guidelines
R E Enabled Suppliers Information Component Cooling Solution Heatsink Development Suppliers Description Copper Fin, Copper Base Fujikura* (stacked fin) CNDA 36187 Furukawa (crimped fin) CNDA 65755 Supplier Contact Info Mechatronics* Steve Carlson 800-453-4569 x205 steve@mechatronics.com Furukawa America Katsu Mizushima (408) 232-9306 katsumizushima@mindspring.
R Enabled Suppliers Information 54 64-bit Intel® Xeon™ Processor MP with 1 MB L2 Cache Thermal/Mechanical Design Guidelines
R F Processor Thermal Management Logic and Thermal Monitor Features F.1 Thermal Management Logic and Thermal Monitor Feature F.1.1 Processor Power Dissipation An increase in processor operating frequency not only increases system performance, but also increases the processor power dissipation. The relationship between frequency and power is generalized in the following equation: P = CV2F (where P = power, C = capacitance, V = voltage, F = frequency).
R Processor Thermal Management Logic and Thermal Monitor Features temperature. By comparing this current with the reference current, the processor temperature can be determined. The reference current source corresponds to the diode current when at the maximum permissible processor operating temperature. Processors are calibrated during manufacturing on a small sample set. Once configured, the processor temperature at which the PROCHOT# signal is asserted (trip point) is not re-configurable. Figure F-1.
R Processor Thermal Management Logic and Thermal Monitor Features F.1.3 Operation and Configuration To maintain compatibility with previous generations of processors, which have no integrated thermal logic, the TCC portion of Thermal Monitor is disabled by default. During the boot process, the BIOS must enable the TCC; or a software driver may do this after the operating system has booted. Thermal Monitor or Thermal Monitor 2 feature must be enabled for the processor to remain within specification.
R Processor Thermal Management Logic and Thermal Monitor Features hysteresis period 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 F-3 for an illustration of this ordering. Figure F-3.
R Processor Thermal Management Logic and Thermal Monitor Features systems that utilize execution based timing routines. The BIOS must disable the TCC prior to boot and then the operating system or BIOS must enable the TCC after the operating system boot process completes. Intel has worked with the major operating system vendors to ensure support for non-execution based operating system calibration loops and ACPI support for the Thermal Monitor feature. F.1.
R Processor Thermal Management Logic and Thermal Monitor Features The on-die thermal diode can be used with an external device (thermal diode sensor) to monitor long-term temperature trends. By averaging this data information over long time periods (hours/days vs. min/sec), it may be possible to derive a trend of the processor temperature. Analysis of this information could be useful in detecting changes in the system environment that may require attention.
R Processor Thermal Management Logic and Thermal Monitor Features F.1.8 Cooling System Failure Warning If desired, the system may be designed to cool the maximum processor power. In this situation, it may be useful to use the PROCHOT# signal as an indication of cooling system failure. Messages could be sent to the system administrator to warn of the cooling failure, while the TCC would allow the system to continue functioning or allow a graceful system shutdown.
R Processor Thermal Management Logic and Thermal Monitor Features 62 64-bit Intel® Xeon™ Processor MP with 1 MB L2 Cache Thermal/Mechanical Design Guidelines
