Intel® Xeon™ Processor with 800 MHz System Bus Thermal/Mechanical Design Guidelines June 2004 Order Number: 302661-001
Notice: This document contains information on products in the design phase of development. Do not finalize a design with this information. Revised information will be published when the product is available. Verify with your local Intel sales office that you have the latest datasheet before finalizing a design.
Contents 1 Introduction.........................................................................................................................7 1.1 1.2 1.3 1.4 2 Objective ...............................................................................................................7 Scope .................................................................................................................... 7 References ......................................................................................
D.1 Intel Verification Criteria for the Reference Designs ........................................... 67 D.1.1 Reference Heatsink Thermal Verification............................................... 67 D.1.2 Environmental Reliability Testing ........................................................... 67 D.1.3 Material and Recycling Requirements.................................................... 69 E Enabled Suppliers Information ............................................................................
A-12 A-13 A-14 A-15 A-16 A-17 A-18 A-19 B-20 B-21 B-22 B-23 B-24 D-25 D-26 F-27 F-28 F-29 F-30 Baseboard Keepout Footprint Definition and Height Restrictions for Enabling Components (sheet 5 of 6)................................................................... 51 Baseboard Keepout Footprint Definition and Height Restrictions for Enabling Components (sheet 6 of 6)................................................................... 52 1U CEK Heatsink (Sheet 1 of 4)..........................................
Revision History 6 Revision Number Order Number 1.0 302661-001 Description Initial release of the document.
1 Introduction 1.1 Objective The objective of this document is to describe the reference thermal solution and design parameters required for the Intel® Xeon™ Processor with 800 MHz System Bus. It is also the intent of this document to comprehend and demonstrate the processor cooling solution features and requirements.
Introduction Table 1-1. Reference Documents Document Comment Thin Electronics Bay Specification (A Server System Infrastructure (SSI) Specification for Rack Optimized Servers - CHECK WITH CENGIZ www.ssiforum.com ntel® Xeon™ Processor with 800 MHz System Bus Mechanical Models http://www.developer.intel.com ntel® Xeon™ Processor with 800 MHz System Bus Enabled Components Thermal Models http://www.developer.intel.
Introduction Table 1-2. Terms and Descriptions (Cont’d) Term Description TDP Thermal Design Power should be used for processor/chipset thermal solution design targets. TDP is not the maximum power that the processor/chipset can dissipate. Thermal Monitor A feature on the processor that can keep the processor’s die temperature within factory specifications under nearly all conditions. Thermal Profile Line that defines case temperature specification of a processor at a given power level.
Introduction 10 Intel® Xeon™ Processor with 800 MHz System Bus Thermal/Mechanical Design Guidelines
2 Thermal/Mechanical Reference Design 2.1 Mechanical Requirements The mechanical performance of the processor cooling solution must satisfy the requirements described in this section. 2.1.1 Processor Mechanical Parameters Table 2-3. Processor Mechanical Parameters Table Parameter Minimum Maximum Unit Volumetric Requirements and Refer to drawings Keepouts in Appendix A Heatsink Mass Static Compressive Load Dynamic Compressive Load 1000 g 2.
Thermal/Mechanical Reference Design 7. Experimentally validated test condition used a heatsink mass of 1 lbm (~0.45 kg) with 100 G acceleration measured at heatsink mass. The dynamic portion of this specification in the product application can have flexibility in specific values, but the ultimate product of mass times acceleration should not exceed this validated dynamic load (1 lbm x 100 G = 100 lb).
Thermal/Mechanical Reference Design Figure 2-1.
Thermal/Mechanical Reference Design The processor connects to the baseboard through a 604-pin surface mount, zero insertion force (ZIF) socket. A description of the socket can be found in the mPGA604 Socket Design Guidelines. The processor package has mechanical load limits that are specified in the processor Intel® Xeon™ Processor with 800 MHz System Bus at 2.80 GHz and 3.60 GHz Datasheet and in Table 2-3.
Thermal/Mechanical Reference Design 2.2 Thermal Requirements A new thermal specification methodology, referred to as the Thermal Profile, is being introduced on the Intel Xeon Processor with 800 MHz System Bus. The intent of the new Thermal Profile specification is to support acoustic noise reduction through fan speed control and ensure the longterm reliability of the processor.
Thermal/Mechanical Reference Design Figure 2-2. Thermal Profile Diagram M A X TT M A X E CC AA SS E TCASE MAX TCASE MAX @ Pcontrol_base Thermal Profile @Pcontrol_Base TCASE Pcontrol_Base TDP Power The higher end point of the Thermal Profile represents the processor’s TDP and the associated maximum case temperature (TCASEMAX).
Thermal/Mechanical Reference Design Intel Xeon Processor with 800 MHz System Bus, the Tcontrol value is obtained by reading a processor model specific register (MSR) and adding this offset value to a base value. The equation for calculating TCONTROL is: Equation 5. TCONTROL = TCONTROL_BASE + Offset Where: TCONTROL_BASE =A fixed base value defined for a given processor generation as published in the processor EMTS.
Thermal/Mechanical Reference Design 2.2.3 Dual Thermal Profile Concept for the Intel® Xeon™ Processor with 800 MHz System Bus The Intel Xeon Processor with 800 MHz System Bus is designed to go into various form factors, including the volumetrically constrained 1U and custom blade form factors. Due to certain limitations of such form factors (i.e. airflow, thermal solution height), it is very challenging to meet the thermal requirements of the processor.
Thermal/Mechanical Reference Design B does not impose any additional risk to Intel’s long-term reliability requirements. Thermal solutions that exceed Thermal Profile B specification are considered incompliant and will adversely affect the long-term reliability of the processor. Refer to the Intel Xeon Processor with 800 MHz System Bus or Chapter 2.2.4 for the Thermal Profile A and Thermal Profile B specifications. Chapter 2.
Thermal/Mechanical Reference Design Profile and hence the long-term reliability requirements. For this purpose, Intel has defined a new parameter, called TCONTROL as explained in Chapter 2.2.2, to be used in FSC designs to ensure that the long-term reliability of the processor is met while keeping the system level acoustic noise down. Figure 2-5 depicts the relationship between TCONTROL and FSC methodology. Figure 2-5.
Thermal/Mechanical Reference Design 2.3.2 Processor 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).
Thermal/Mechanical Reference Design Figure 2-6. Processor Thermal Characterization Parameter Relationships ΨS HEATSINK TS TIM PROCESSOR TCASE IHS ΨC SOCKET 2.3.2.1 Example The cooling performance, ΨCA, is then defined using the principle of thermal characterization parameter described above: • Define a target case temperature TCASE-MAX and corresponding TDP at a target frequency, F, given in the Intel® Xeon™ Processor with 800 MHz System Bus at 2.80 GHz and 3.60 GHz Datasheet.
Thermal/Mechanical Reference Design Equation 11. ΨSA = ΨCA - ΨCS = 0.27 - 0.05 = 0.22 °C/W If the local processor ambient temperature is assumed to be 40°C, the same calculation can be carried out to determine the new case-to-ambient thermal resistance: Equation 12. ΨCA = (TCASE – TLA) / TDP = (68 – 40) / 85 = 0.
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.
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.
Thermal/Mechanical Reference Design 2.4.4.2 Assembly Drawing Figure 2-7. Exploded View of CEK Thermal Solution Components The CEK reference thermal solution is designed to extend air-cooling capability through the use of larger heatsinks with minimal airflow blockage and bypass. CEK retention solution can allow the use of much heavier heatsink masses compared to the legacy limits by using a load path directly attached to the chassis pan.
Thermal/Mechanical Reference Design heatsink needs to be 0.06 cm. [0.024 in] longer for a 0.231 cm [0.093 in] thick board, compared to a 0.157 cm [0.062 in] thick board. .If this solution is intended to be used on baseboards that fall outside of this range, then some aspects of the design, including but not limited to the hat spring design and the standoff heights, may need to change.
Thermal/Mechanical Reference Design Figure 2-8. 2U+ CEK Heatsink Thermal Performance 0.55 0.80 0.50 0.70 0.45 0.60 0.40 0.50 0.35 0.40 0.30 0.30 0.25 0.20 -0.9397 Mean Ψ == 0.2269 + 1.2225*CFM Mean 0.2269 + 1.2225*CFM-0.9397 caca C/W σ ==0.0086 0.0086 C/W 0.20 0.15 0 10 20 30 40 50 60 70 80 90 inchwater water ∆P,P,inch , C/W Ψca,caC/W 2 2 P∆P = 5.52e-05CFM + 5.24e-03CFM = 5.52e-05CFM + 5.24e-03CFM 0.10 0.
Thermal/Mechanical Reference Design Figure 2-13 below shows the comparison of this reference thermal solution’s Thermal Profile to the Intel Xeon Processor with 800 MHz System Bus Thermal Profile A specification. The 2U+ CEK solution meets the Thermal Profile A with a 2.5 °C margin at the lower end (Pcontrol_base_A) and a 0.4 °C margin at the upper end (TDP).
Thermal/Mechanical Reference Design Figure 2-9. 1U CEK Thermal Adherence to Intel® Xeon™ Processor with 800 MHz System Bus Thermal Profile B 90 TCASE_MAX_B @ TDP 80 Thermal Profile B y = 0.35 * x + 44 70 60 Tcase [°C] TCASE_MAX @ 50 Pcontrol_base 1U CEK Reference Solution y = 0.384 * x + 40 40 30 20 10 0 0 10 20 PCONTROL_BASE_A 30 40 50 60 70 Power [W] 2.4.7 Components Overview 2.4.7.
Thermal/Mechanical Reference Design Figure 2-10. Isometric View of the 2U+ CEK Heatsink Note: Refer to Appendix A for more detailed mechanical drawings of the heatsink. Figure 2-11. Isometric View of the 1U CEK Heatsink Note: Refer to Appendix A for more detailed mechanical drawings of the heatsink. The function of the standoffs is to provide a bridge between the chassis and the heatsink for attaching and load carrying.
Thermal/Mechanical Reference Design Although the CEK heatsink fits into the legacy volumetric keep-in, it has a larger footprint due to the elimination of retention mechanism and clips used in the older enabled thermal/mechanical components. This allows the heatsink to grow its base and fin dimensions, further improving the thermal performance. A drawback of this enlarged size and use of copper for both the base and fins is the increased weight of the heatsink.
Thermal/Mechanical Reference Design 2.4.7.3 Hat Spring The hat spring, which is attached on the secondary side of the baseboard, is made from 0.80 mm [0.0315 in.] thick 301 stainless steel half hard. Any future versions of the spring will be made from a similar material. The hat spring has four embosses (called “hats”) which, when assembled, rest on the top of the chassis standoffs. The hat spring is located between the chassis standoffs and the heatsink standoffs.
Thermal/Mechanical Reference Design 2.4.8 Reference Active Thermal Solution for the Intel® Xeon™ Processor with 800 MHz System Bus In addition to the 1U and 2U passive CEK heatsinks, Intel is developing an active version of the CEK heatsink for the Intel Xeon Processor with 800 MHz System Bus targeted at workstation chassis as well as server chassis which are 3U and above in height. All three heatsinks will be offered as part of boxed Intel Xeon Processor with 800 MHz System Bus products.
Thermal/Mechanical Reference Design 2.5 Electrical Requirements 2.5.1 Fan Power Supply (Active CEK) Initially the boxed Intel Xeon Processor with 800 MHz System Bus will be introduced with a 3-pin active fan heatsink solution, This heatsink solution requires a constant +12 V supplied to pin 2 and does not support variable voltage speed control or 3-pin PWM control. Fan RPM is automatically varied based on the TINLET temperature measured by a thermistor located at the fan inlet.
Thermal/Mechanical Reference Design Figure 2-15. Fan Cable Connector Pin Out (3-Pin Active CEK Heatsink) Table 2-19. Fan Cable Connector Pin Out (3-Pin Active CEK Heatsink) Pin Number 1 Signal Color Ground: Black 2 Power: (+12 V) Yellow 3 Sense: 2 pulses per revolution Green Figure 2-16. Fan Cable Connector Pin Out (4-Pin Active CEK Heatsink) Table 2-20.
Thermal/Mechanical Reference Design Table 2-21. Fan Cable Connector Supplier & Part Number Vendor AMP Walden Molex 2.5.1.
Thermal/Mechanical Reference Design The other items that are required to compete this solution will be shipped with either the chassis or boards.
Mechanical Drawings A The mechanical drawings included in this appendix. These drawings refer to the thermal mechanical enabling components for the Intel Xeon Processor with 800 MHz System Bus. Note: Intel reserves the right to make changes and modifications to the design as necessary. Table A-1.
Mechanical Drawings Figure A-1.
Mechanical Drawings Figure A-2.
Mechanical Drawings Figure A-3.
Mechanical Drawings Figure A-4.
Mechanical Drawings Figure A-5.
Mechanical Drawings Figure A-6.
Mechanical Drawings Figure A-7.
Mechanical Drawings Figure A-8.
Mechanical Drawings Figure A-9.
Mechanical Drawings Figure A-10.
Mechanical Drawings Figure A-11.
Mechanical Drawings Figure A-12.
Mechanical Drawings Figure A-13.
Mechanical Drawings Figure A-14.
Mechanical Drawings 2 Figure A-15.
Mechanical Drawings Figure A-16.
Mechanical Drawings Figure A-17.
Mechanical Drawings Figure A-18.
Mechanical Drawings Figure A-19.
Test Setup Methodology B B.1 Thermal Metrology B.1.1 Processor Thermal Solution Performance Assessment This section discusses guidelines for testing thermal solutions, including measuring processor temperatures. In all cases, the thermal engineer must measure power dissipation and temperature to validate a thermal solution. Thermal performance of a heatsink should be assessed using a thermal test vehicle (TTV) provided by Intel.
Test Setup Methodology B.1.2 Thermocouple Attachment, Air Temperature and Velocity Measurements Hysol Epoxy-Patch #309* or equivalent may be used for bonding thermocouples to the heat sources. A good thermal bond between the thermocouple and the device being measured is essential. However, excessive bonding material can affect the measurement for small devices particularly if the bonding material has a significantly different thermal conductivity compared to the device being tested.
Test Setup Methodology Note: The processor and TTV are extremely fragile components. To avoid damage, it is very important that special attention be given when milling a channel into the IHS. Figure B-20. 0° Attachment Method For illustration, the measurement location for a 42.5 mm x 42.5 mm [1.673 in. x 1.673 in.] flipchip micro pin grid array 4 (FC-mPGA4) package with 31 mm x 31 mm [1.22 in. x 1.22 in.] IHS is shown in Figure B-21.
Test Setup Methodology Figure B-22. Local Air Thermocouple Placement for Passive Heatsinks T T L A a H e a ts in k H e a tsin k X -S e c tio n a lV ie w X -S e ctio n a lV ie w For active heatsinks, four thermocouples will be placed on the fan inlet as shown Figure B-23. These thermocouples will be mounted between 5mm and 10mm above the fan. The average of these measurements will be used to represent the local inlet temperature to the active heatsink. Figure B-23.
Test Setup Methodology Figure B-24.
Test Setup Methodology 64 Intel® Xeon™ Processor with 800 MHz System Bus Thermal/Mechanical Design Guidelines
Safety Requirements C 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. • ESA Certification. All mechanical and thermal enabling components must have CSA certification. • Heatsink fins must meet the test requirements of UL1439 for sharp edges.
Safety Requirements 66 Intel® Xeon™ Processor with 800 MHz System Bus Thermal/Mechanical Design Guidelines
Quality and Reliability Requirements D 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.1, and using a TTV. 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 (based on the TTV correction offset). D.1.
Quality and Reliability Requirements Figure D-25. Random Vibration PSD 0.1 3.13 GRMS (10 Minutes Per Axis) PSD (g^2/Hz) (20, 0.02) (500, 0.02) (5, 0.01) 0.01 5 Hz 500 Hz 0.001 1 D.1.2.3 10 Frequency (Hz) 100 1000 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.
Quality and Reliability Requirements D.1.2.4 Recommended Test Sequence Each test sequence should start with components (i.e. baseboard, heatsink assembly, etc.) that have not been previously submitted to any reliability testing. The test sequence should always start with a visual inspection after assembly, and BIOS/Processor/ memory test. The stress test should be then followed by a visual inspection and then BIOS/ Processor/memory test. D.1.2.
Quality and Reliability Requirements Any plastic component exceeding 25 grams must be recyclable per the European Blue Angel recycling standards.
Enabled Suppliers Information E Table E-3. Enabled Suppliers Component Development Suppliers Description Fujikura* (stacked fin) CNDA 36187 CEK Heatsink Mechatronics* Steve Carlson 800-453-4569 x205 steve@mechatronics.com Copper Fin, Copper Base Furukawa* (crimped fin) CNDA 65755 Thermal Interface Material Supplier Contact Info Grease Shin-Etsu* G751 CNDA 75610 Furukawa America* Katsu Mizushima (408) 232-9306 katsumizushima@mindspring.
Enabled Suppliers Information 72 Intel® Xeon™ Processor with 800 MHz System Bus Thermal/Mechanical Design Guidelines
Processor Thermal Management Logic and Thermal Monitor Features F 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).
Processor Thermal Management Logic and Thermal Monitor Features 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-27.
Processor Thermal Management Logic and Thermal Monitor Features Performance counter registers, status bits in model specific registers (MSRs), and the PROCHOT# output pin are available to monitor and control the Thermal Monitor behavior. Figure F-28. Concept for Clocks under Thermal Monitor Control PROCHOT# Normal clock Core clock w/ TM2 Engaged VID w/ TM2 Engaged F.1.
Processor Thermal Management Logic and Thermal Monitor Features 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 (bus-to-core multiplier) and input voltage identification (VID) value. This combination of reduced frequency and the lowering of VID results in a reduction in processor power consumption.
Processor Thermal Management Logic and Thermal Monitor Features Note: Intel requires the TCC to be enabled for all Intel Xeon Processor with 800 MHz System Bus based systems. At a minimum, the TCC provides an added level of protection against processor thermal solution failure. A system designed to meet the TDP and TCASE targets published in the processor Intel® Xeon™ Processor with 800 MHz System Bus at 2.80 GHz and 3.
Processor Thermal Management Logic and Thermal Monitor Features System integrators that plan on using the thermal diode for system or component level fan control need to be aware of the potential for rapid changes in processor power consumption as the executing workload changes. Variable performance thermal solutions that fail to react quickly to changing workloads may experience TCC activation or worse yet, result in automatic shutdown via THERMTRIP# (refer to Appendix F.1.7.
Processor Thermal Management Logic and Thermal Monitor Features F.1.7.2 THERMTRIP# Signal Pin In the event of a catastrophic cooling failure, the processor will automatically shut down when the silicon temperature has reached its operating limit. At this point the system bus signal THERMTRIP# signal goes active and power must be removed from the processor. THERMTRIP# stays active until RESET# has been initiated.
Processor Thermal Management Logic and Thermal Monitor Features 80 Intel® Xeon™ Processor with 800 MHz System Bus Thermal/Mechanical Design Guidelines
