Intel Xeon Processor with 800 MHz System Bus Thermal/Mechanical Design Guide

Intel® Xeon™ Processor with 800 MHz System Bus Thermal/Mechanical Design Guidelines 59
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. The TTV is a well-characterized thermal tool, whereas real 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, Intel recommends OEMs use
this tool in conjunction with other design and verification methods to verify their cooling solution
meets the specifications outlined in the product datasheet. A tool, by itself, should not be used to
determine compliance of a thermal design to the processor’s thermal specifications.
B.1.1.1 TTV Correction Factor for Intel® Xeon™ Processor with 800 MHz
System Bus
Thermal characterization parameter measurements made with a TTV must be corrected for the
non-uniform power dissipation of actual processors. Table B- 2 provides correction factor for using
an Intel® Xeon™ processor with 512 KB L2 cache TTV to assess the thermal characterization
parameter of Intel Xeon Processor with 800 MHz System Bus heatsinks. The value of a thermal
characterization parameter is derived from the value measured on the TTV and the corresponding
correction offset according to equation:
Equation B-1. {Processor Ψ
CA
} = {TTV Ψ
CA
} + Correction offset
The correction factor should be applied to a mean + 3sigma value when testing with a statistical
sample size.
Table B-2. Intel® Xeon™ Processor with 800 MHz System Bus Thermal Characterization
Parameter CorrectionOffset for TTV
Thermal Characterization Parameter (°C/W)
Correction Offset Intel Xeon Processor with
512-KB L2 cache TTV (°C/W)
Ψ
CA
0.02