Intel Pentium 4 Processor with 512-KB L2 Cache on 0.13 Micron Process Thermal Design Guidelines

Thermal Specifications
R
16 Intel
®
Pentium
®
4 Processor Thermal Design Guide
3.2.2 Looking at the Whole Thermal Solution
3.2.2.1 Chassis Thermal Design Capabilities
Only chassis capable of T
A
equal or lower than 45°C can be used for the Pentium 4 Processor with
512-KB L2 Cache on 0.13 micron process to support frequencies between 1.20 GHz thru
2.80 GHz. Chassis that do not meet this recommendation may require more sophisticated, and thus
more expensive, cooling solution on the processor to compensate the lack of performance of the
chassis.
It is expected that chassis thermal capabilities are improved and can deliver T
A
no greater than
42°C for processor frequencies at 3.06 GHz or higher. Refer to Section 3.2.2.2 below for further
information.
3.2.2.2 Improving Chassis Thermal Performance
The heat generated by components within the chassis must be removed to provide an adequate
operating environment for both the processor and other system components. Moving air through
the chassis brings in air from the external ambient environment and transports the heat generated
by the processor and other system components out of the system. The number, size and relative
position of fans and vents have a decisive impact on the chassis thermal performance, and
therefore on the ambient temperature around the processor. The size and type (passive or active)
of the thermal cooling device and the amount of system airflow are related and can be traded off
against each other to meet specific system design constraints. Additional constraints are board
layout, spacing, component placement, and structural considerations that limit the thermal solution
size. For more information, refer to the Performance ATX Desktop System Thermal Design
Suggestions or Performance microATX Desktop System Thermal Design Suggestions documents
available on the http://www.formfactors.org/
web site.
In addition to passive heatsinks, fan heatsinks and system fans, other solutions exist for cooling
integrated circuit devices. For example, ducted blowers, heat pipes and liquid cooling are all
capable of dissipating additional heat. Due to their varying attributes, each of these solutions may
be appropriate for a particular system implementation.
To develop a reliable, cost-effective thermal solution, thermal characterization and simulation
should be carried out at the system level, accounting for the thermal requirements of each
component. In addition, acoustic noise constraints may limit the size, number, placement, and
types of fans that can be used in a particular design.
To ease the burden on cooling solutions, the Thermal Monitor feature and associated logic have
been integrated into the silicon of the Pentium 4 processor with 512-KB L2 cache on 0.13 micron
process. By taking advantage of the Thermal Monitor feature, system designers may reduce the
cooling system cost while maintaining the processor reliability and performance goals.
Implementation options and recommendations are described in Section 3.4.