Intel Pentium 4 Processor In the 423-pin Package Thermal Design Guidelines

Pentium® 4 processor in the 423-pin package Thermal Design Guidelines

1 INTRODUCTION

In a system environment, the processor's temperature is a function of both the system and component thermal

characteristics. The system level thermal constraints consist of the local ambient temperature at the processor and

the airflow over the processor as well as the physical constraints at and above the processor. The processor’s

temperature depends on the component power dissipation, size and material (effective thermal conductivity) of the

integrated heat spreader, and the presence of a thermal cooling solution.

All of these parameters are aggravated by the continued push of technology to increase performance levels (higher

operating speeds, MHz) and packaging density (more transistors). As operating frequencies increase and packaging

size decreases, the power density increases and the thermal cooling solution space and airflow become more

constrained. The result is an increased importance on system design to ensure that thermal design requirements are

met for each component in the system.

All dimensions in this document, unless otherwise noted, are in inches.

1.1 Document Goals

The thermal power of the Pentium® 4 processor generation is higher, as well as denser, than previous Intel

architecture processors. Depending on the type of system and the chassis characteristics, new system designs may be

required to provide adequate cooling for the processor. The goal of this document is to provide an understanding of

these thermal characteristics and discuss guidelines for meeting the thermal specifications.

1.2 Document Scope

This document discusses thermal management techniques for the Pentium 4 processor, which is primarily intended

for the performance desktop segment. It will also address the issues of the integrated thermal management logic and

its impact on thermal design.

The physical dimensions and power numbers used in this document are for reference only. Please refer to the

Pentium 4 processor in the 423-pin Package Datasheet

for the product dimensions, thermal power dissipation and

maximum case temperature. In case of conflict, the data in the Datasheet supercedes any data in this document.

1.3 References

• Pentium 4 processor in the PGA423 Package Datasheet

• IA32 Intel Architecture Software Developer Manuals Volumes 1-3

• Pentium 4 processor and Intel® 850 Chipset Platform Design Guidelines

• 423 Pin Socket (PGA423) Design Guidelines

For details on ordering this documentation, contact your Intel field sales representative or visit the Intel web site

http://developer.intel.com/.

1.4 Definition of Terms

•

- the measured ambient temperature locally surrounding the processor. The ambient temperature should be

measured just “upstream” of a passive heat sink, or at the fan inlet for an active heat sink (see Figure 7).

•

AMBIENT-OEM

- the target worst-case ambient temperature at a given

external

system location as defined by the

system designer (OEM).