64-bit Intel Xeon Processor with 2MB L2 Cache Thermal/Mechanical Design Guidelines

64-bit Intel® Xeon™ Processor with 2MB L2 Cache Thermal/Mechanical Design Guidelines 37
Thermal/Mechanical Reference Design
2.4.8.2 Systems Considerations Associated with the Active CEK
This heatsink was designed to help pedestal chassis users to meet the thermal processor
requirements without the use of chassis ducting. It may be necessary to implement some form of
chassis air guide or air duct to meet the T
LA
temperature of 40 °C depending on the pedestal
chassis layout. Also, while the active heatsink solution is designed to mechanically fit into a 2U
chassis, it may require additional space at the top of the heatsink to allow sufficient airflow into the
heatsink fan. Therefore, additional design criteria may need to be considered if this heatsink is used
in a 2U rack mount chassis, or in a chassis that has drive bay obstructions above the inlet to the fan
heatsink.
Thermal Profile A should be used to help determine the thermal performance of the platform. The
primary recommended control method for this solution is using pulse width modulation control.
This control method requires the motherboard provide the correct PWM duty cycle to the active
fan heatsink solution to properly follow the thermal profile. If no PWM signal is detected the active
heatsink solution will default back to a thermistor controlled mode and the fan will automatically
adjust fan RPM to meet the thermal profile.
It is critical to supply a constant +12 V to the fan header so that the active CEK heatsink solution
can operate properly. If a system board has a jumper setting to select either a constant +12 V power
to the fan header or a variable voltage, it is strongly recommended that the jumper be set by default
to the constant +12 V setting.
It is recommended that the ambient air temperature outside of the chassis be kept at or below 35
°C. The air passing directly over the processor heatsink should not be preheated by other system
components. Meeting the processor’s temperature specification is the responsibility of the system
integrator.
2.4.8.3 Boxed Processor Contents
A direct chassis attach method must be used to avoid problems related to shock and vibration, due
to the weight of the heatsink required to cool the processor. The board must not bend beyond
specification in order to avoid damage. The boxed processor contains the components necessary to
solve both issues. The boxed processor will include the following items:
• 64-bit Intel Xeon Processor with 2MB L2 Cache
• Unattached (Active or Passive) Heatsink
• 4 screws, 4 springs, and 4 heatsink standoffs (all captive to the heatsink)
• Thermal Interface Material (TIM)
• Certificate of Authenticity (COA) and Manual
• Intel Inside Logo
The other items listed in Figure 2-8 that are required to complete this solution will be shipped with
either the chassis or boards. They are as follows:
• CEK Spring (supplied by baseboard vendors)
• Chassis standoffs (supplied by chassis vendors)
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