Intel 5400 Series Processor Thermal Parameters and Features, Thermal Control Circuit and TDP

Thermal/Mechanical Reference Design

A potential mechanical solution for heavy heatsinks is the direct attachment of the heatsink to the chassis pan. In this case, the strength of the chassis pan can be utilized rather than solely relying on the baseboard strength. In addition to the general guidelines given above, contact with the baseboard surfaces should be minimized during installation in order to avoid any damage to the baseboard.

The Intel reference design for Quad-Core Intel® Xeon® Processor 5400 Series is using such a heatsink attachment scheme. Refer to Section 2.5 for further information regarding the Intel reference mechanical solution.

2.2Processor Thermal Parameters and Features

2.2.1Thermal Control Circuit and TDP

The operating thermal limits of the processor are defined by the Thermal Profile. The intent of the Thermal Profile specification is to support acoustic noise reduction through fan speed control and ensure the long-term reliability of the processor. This specification requires that the temperature at the center of the processor IHS, known as (TCASE) remains within a certain temperature specification. For illustration, Figure 2-4shows the measurement location for the Quad-Core Intel® Xeon® Processor 5400 Series package. Compliance with the TCASE specification is required to achieve optimal operation and long-term reliability (See the Intel® Xeon® Dual- and Multi- Processor Family Thermal Test Vehicle User's Guide for Case Temperature definition and measurement methods).

Figure 2-4. Processor Case Temperature Measurement Location

To ease the burden on thermal solutions, the Thermal Monitor feature and associated logic have been integrated into the silicon of the processor. One feature of the Thermal Monitor is the Thermal Control Circuit (TCC). When active, the TCC lowers the processor temperature by reducing power consumption. This is accomplished through a combination of Thermal Monitor and Advanced Thermal Monitor (TM2). Thermal Monitor modulates the duty cycle of the internal processor clocks, resulting in a lower effective frequency. When active, the TCC turns the processor clocks off and then back on with a predetermined duty cycle. Thermal Monitor 2 activation adjusts both the

Quad-Core Intel® Xeon® Processor 5400 Series TMDG 19