Intel
®
945G Express Chipset GMCH Thermal Design Guide
Introduction
1 Introduction
As the complexity of computer systems increases, so do power dissipation requirements. The
additional power of next generation systems must be properly dissipated. Heat can be dissipated
using improved system cooling, selective use of ducting, and/or passive heat sinks.
The objective of thermal management is to ensure that the temperatures of all components in a
system are maintained within functional limits. The functional temperature limit is the range
within which the electrical circuits can be expected to meet specified performance requirements.
Operation outside the functional limit can degrade system performance, cause logic errors, or
cause component and/or system damage. Temperatures exceeding the maximum operating limits
may result in irreversible changes in the operating characteristics of the component. The goal of
this document is to provide an understanding of the operating limits of the Intel
®
945G Graphics
and Memory Controller Hub (GMCH) Chipset and discuss a reference thermal solution.
The simplest and most cost-effective method to improve the inherent system cooling
characteristics of the GMCH is through careful design and placement of fans, vents, and ducts.
When additional cooling is required, component thermal solutions may be implemented in
conjunction with system thermal solutions. The size of the fan or heat sink can be varied to
balance size and space constraints with acoustic noise.
This document presents the conditions and requirements to properly design a cooling solution for
systems that implement the 945G Express Chipset GMCH. Properly designed solutions provide
adequate cooling to maintain the 945G Express Chipset GMCH case temperature at or below
thermal specifications. This is accomplished by providing a low local-ambient temperature,
ensuring adequate local airflow, and minimizing the case to local-ambient thermal resistance. By
maintaining the 945G Express Chipset GMCH case temperature at or below those recommended
in this document, a system designer can ensure the proper functionality, performance, and
reliability of this chipset.
1.1 Scope
This document applies only to the implementation of the 945G Express Chipset GMCH in the 1U
and larger server form factors. For more information on server system form factors visit,
www.ssiforum.org
. For information on the desktop computer application of the 945G Express
Chipset GMCH, refer to the
Intel
®
945G/945P Express Chipset Family Thermal and Mechanical
Design Guidelines.
1.2 Terminology
Term Description
BGA
Ball grid array. A package type defined by a resin-fiber substrate where a die is mounted
and bonded. The primary electrical interface is an array of solder balls attached to the
substrate opposite the die and molding compound.
FC-BGA
Flip chip ball grid array. A package type defined by a plastic substrate where a die is
mounted using an underfill C4 (Controlled Collapse Chip Connection) attach style. The
primary electrical interface is an array of solder balls attached to the substrate opposite the
die. Note that the device arrives at the customer with solder balls attached.
Intel
®
ICH7
Intel
®
I/O Controller Hub 7. The chipset component that contains the primary PCI interface,
LPC interface, USB, ATA, and/or other legacy functions.
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