Intel 5100 Series Instruction Manual page 47

Thermal/Mechanical Reference Design
from components available through distribution channels. The retention solution used
for these products is called the CEK. The CEK base is compatible with all the heatsink
solutions.
Figure 2-25
on a 4-pin PWM PECI/DTS controlled active fan heatsink solution. PWM (Pulse Width
Modulation also synonymous with Pulse Duration Modulation PDM) is a modulation in
which the duration of pulse is varied in accordance with some characteristic of the
modulating signal. This new solution is being offered to help provide better control over
pedestal chassis acoustics. This is achieved though accurate measurement of processor
temperature through the processor's Digital Thermal Sensor (DTS) temperature. Fan
RPM is modulated through the use an ASIC (Application Specific Integrated Circuit)
located on the serverboard, that sends out a PWM control signal to the 4
connector labeled as Control.
This heatsink solution also requires a constant +12 V supplied to pin 2 and does not
support variable voltage control or 3-pin PWM control. If no PWM signal is detected on
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the 4 pin this heatsink solution will revert back to thermistor control mode,
supporting both the 4-wire PWM and standard 3-wire ambient air control methods.
The active heatsink solution will not exceed a mass of approximately 1050 grams. Note
that this is per processor, so a dual processor system will have up to approximately
2100 grams total mass in the heatsinks. This large mass will require a minimum
chassis stiffness to be met in order to withstand force during shock and vibration.
Figure 2-25. Boxed Active CEK Heatsink Solutions with PWM/DTS Control
(Representation Only)
Clearance is required around the heatsink to ensure unimpeded airflow for proper
cooling. The physical baseboard keepout requirements for the active solution are the
same as the passive CEK solution shown in
Figure A-20
2.4.8.1 Fan Power Supply
The active heatsink includes a fan, which requires a +12 V power supply. Platforms
must provide a matched fan power header to support the boxed processor.
contains specifications for the input and output signals at the heatsink fan connector.
Dual-Core Intel® Xeon® Processor 5100 Series Thermal/Mechanical Design Guide
provides a representation of the active CEK solution. This design is based
for additional details on the active CEK thermal solution volumetrics.
Appendix A. Refer to Figure A-18
th
pin of the
through
Table 2-10
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