Guide

Thermal and Mechanical Design
Intel® Xeon® Processor E7 2800/4800/8800 v2 Product Family 51
Thermal/ Mechanical Specifications and Design Guide
Thermal boundary conditions are applied in establishing the processor heatsink cooling solution.
2.3.6 Thermal Solution Performance Characterization
The case-to-local ambient Thermal Characterization Parameter (Ψ
CA
) is defined by:
Equation 2-1.Ψ
CA
= (T
CASE
- T
LA
) /
TDP
Where:
T
CASE
= Processor case temperature (°C).
T
LA
= Local ambient temperature in chassis at processor (°C).
TDP = TDP (W) assumes all power dissipates through the integrated heat
spreader. This inexact assumption is convenient for heatsink design.
TTVs are often used to dissipate TDP. Correction offsets account for
differences in temperature distribution between processor and TTV.
Equation 2-2.Ψ
CA
= Ψ
CS
+ Ψ
SA
Where:
Ψ
CS
= Thermal characterization parameter of the TIM (°C/W) is dependent
on the thermal conductivity and thickness of the TIM.
Ψ
SA
= Thermal characterization parameter from heatsink-to-local ambient
(°C/W) is dependent on the thermal conductivity and geometry of the
heatsink and dependent on the air velocity through the heatsink fins.
Figure 2-27 illustrates the thermal characterization parameters.
Table 2-15. Thermal Solution Performance Design Targets and Environment
Parameter Maximum Unit Notes
T
LA
47 °C
This is the temperature at the processor
cooling devices.
Pressure Drop (
ΔP) 57.2 (0.23) Pa (inch H
2
O)
Total pressure drop across the processor
heatsink fins with zero bypass.
Altitude Sea-level Heatsink designed at 0 meters
Airflow 15.8 (33.5) l/s (CFM) Airflow through the heatsink fins.
Figure 2-27. Processor Thermal Characterization Parameter Relationships