Intel Core2 Duo Desktop Processor, Intel Pentium Processor, and Intel Pentium 4 Processor 6x1 Sequence

Thermal Metrology
Thermal and Mechanical Design Guidelines 29
Assume the TDP, as listed in the datasheet, is 100 W and the maximum case
temperature from the thermal profile for 100W is 67 °C. Assume as well that the
system airflow has been designed such that the local ambient temperature is 38 °C.
Then the following could be calculated using equation 1 from above:
Ψ
CA
= (T
C,
– T
A
) / TDP = (67 – 38) / 100 = 0.29 °C/W
To determine the required heatsink performance, a heatsink solution provider would
need to determine Ψ
CS
performance for the selected TIM and mechanical load
configuration. If the heatsink solution were designed to work with a TIM material
performing at Ψ
CS
≤ 0.10 °C/W, solving for equation 2 from above, the performance of
the heatsink would be:
Ψ
SA
= Ψ
CA
− Ψ
CS
= 0.29 − 0.10 = 0.19 °C/W
3.2 Processor Thermal Solution Performance
Assessment
Thermal performance of a heatsink should be assessed using a thermal test vehicle
(TTV) provided by Intel. The TTV is a stable heat source that the user can make
accurate power measurement, whereas processors can introduce additional factors
that can impact test results. In particular, the power level from actual processors
varies significantly, even when running the maximum power application provided by
Intel, due to variances in the manufacturing process. The TTV provides consistent
power and power density for thermal solution characterization and results can be
easily translated to real processor performance. Accurate measurement of the power
dissipated by an actual processor is beyond the scope of this document.
Once the thermal solution is designed and validated with the TTV, it is strongly
recommended to verify functionality of the thermal solution on real processors and on
fully integrated systems. The Intel maximum power application enables steady power
dissipation on a processor to assist in this testing. This application is called Maximum
Power Program for the Processor (Intel
®
Core
™
2 Duo or Intel
®
Pentium
®
4 Processor
6x1 Sequence). Contact your Intel Field Sales representative for a copy of the latest
release of this application.