Thermal Management for Intel® Pentium® 4 Processors in the 478/423 Pin Package
The information covers thermal management for Boxed Intel® Pentium® 4 Processors in both the 478-pin and 423-pin packages.
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Introduction
Systems using Intel® Pentium® 4 Processors all require thermal management. Integrators who follow the recommendations can provide customers with more reliable systems and see fewer customers returning with thermal management issues. Boxed Intel Pentium 4 Processors refer to processors packaged for system integrators.
Thermal management in boxed Intel Pentium 4 Processor-based systems can affect the system:
- Performance - Thermal Monitor feature
- Noise level - Variable speed fan
The Intel Pentium 4 Processor uses the Thermal Monitor feature to protect the processor during times where the silicon would otherwise operate above specification. The feature helps prevent long-term reliability damage to the processor and provides protection for unusual circumstances such as:
- Internal chassis temperatures and inlet air temperature are higher than usual. The air temperature entering the processor fan heatsink is unusually hot.
- Failure of a system thermal management component, such as a system fan.
In addition to the Thermal Monitor feature, the boxed Intel Pentium 4 Processor fan heatsink uses a high-quality variable speed fan. The fan allows the processor to remain within its operating thermal specifications. The processor fan operates at a low speed while internal chassis temperatures are low. If internal chassis temperatures increases beyond a lower set point, the fan speed increases until it reaches the higher set point. As fan speed increases, so does the noise that the fan generates. Ideally, the system design provides air around the boxed processor fan heatsink below the lower set point. These set points in Table 1 and Figure 1 can vary between different fan heatsinks by a few degrees.
Table 1. Boxed Processor Fan Heatsink Set Points
Boxed Intel Pentium 4 Processors in the 423-pin Package: | |
Internal Chassis Temperature (oC) | Boxed Processor Fan Heatsink Set Points |
X < = 361 | Lower Set Point: Fan speed constant at lowest fan speed. Recommended temperature for nominal operating environment. |
Y = 401 | Recommended maximum internal chassis temperature for boxed Intel Pentium 4 Processor-based systems. |
X > = 451 or greater | Higher Set Point: Fan speed constant at highest fan speed. |
Boxed Intel Pentium 4 Processors in the 478-pin Package at 2.80 GHz (and below): | |
Internal Chassis Temperature (oC) | Boxed Processor Fan Heatsink Set Points |
X < = 331 or less | Lower Set Point: Fan speed constant at lowest fan speed. Recommended temperature for nominal operating environment. |
Y = 401 | Recommended maximum internal chassis temperature for boxed Intel Pentium 4 Processor-based systems. |
X > = 431 or greater | Higher Set Point: Fan speed constant at highest fan speed. |
Boxed Intel Pentium 4 Processors in the 478-pin Package at 3 GHz (and above): | |
Internal Chassis Temperature (oC) | Boxed Processor Fan Heatsink Set Points |
X < = 321 or less | Lower Set Point: Fan speed constant at lowest fan speed. Recommended temperature for nominal operating environment. |
Y = 381 | Recommended maximum internal chassis temperature for boxed Intel Pentium 4 Processor-based systems. |
X > = 401 | Higher Set Point: Fan speed constant at highest fan speed. |
Figure 1. Internal Chassis Temperature Impact On Noise
You can affect processor life and reliably if you allow operation at temperatures beyond the maximum. Meeting the temperature specification is ultimately the responsibility of the system integrator. When building systems using the boxed Intel Pentium 4 Processor, consider the thermal management of the system and verify the design with thermal testing. View the sections below for specific thermal requirements of the boxed Intel Pentium 4 Processor. We recommend system integrators using the boxed Pentium 4 Processor become familiar with this content.
Thermal management
Proper thermal management depends on two major elements:
- A heatsink properly mounted to the processor
- Effective airflow through the system chassis
Proper thermal management occurs when heat transfers from the processor to the system air, which then vents out of the system. Boxed Intel Pentium 4 Processors ship with a high-quality, variable speed fan heatsink to effectively transfer processor heat to the system air. The system integrator has the responsibility to ensure adequate system airflow.
Installing the fan heatsink
Ensure the fan heatsink included with the boxed Intel Pentium 4 Processor is securely attached to the processor. Thermal interface material provides effective heat transfer from the processor to the fan heatsink. The material is either attached to the bottom of the heatsink or applied during system integration with an applicator. The fan cable connects to a motherboard-mounted power header to provide power to the fan. This connection also allows the fan to provide fan speed information to the motherboard. Only motherboards with hardware monitoring circuitry can use the fan speed signal. Follow the installation procedures documented in the boxed processor manual and the Integration Overview for either:
- Boxed Intel Pentium 4 Processor in the 423-pin package
- Boxed Intel Pentium 4 Processor in the 478-pin package
The fan is a high-quality ball bearing fan that provides a local air stream. This air stream transfers heat from the heatsink to the air inside the system. However, moving heat to the system air is only half the task. You need sufficient system airflow to exhaust the air. Without steadily streaming air through the system, the fan heatsink recirculates warm air and may not cool the processor adequately.
Replacing thermal interface material for fan heatsink
Thermal interface material is required for proper heat transfer from the processor to the fan heatsink. The boxed Intel Pentium 4 Processor either has:
- Thermal interface material attached to the heatsink
We do not recommend removing the thermal interface material on the bottom of the boxed processor fan heatsink. Removing this material may damage the processor and voids the boxed processor warranty. If you must remove and reuse the fan heatsink, it requires replacement. Also, if there is damage to the thermal interface material, you must replace the material or the fan heatsink. Contact Intel Customer Support for assistance. - Thermal interface material in an applicator
Using the boxed processor without properly applying thermal interface material may damage the processor and voids the boxed processor warranty. If you must remove and reuse the fan heatsink, a you need new application of thermal interface material. Contact Intel Customer Support to receive more thermal interface material in an applicator.
Chassis recommendations
Chassis depends on the motherboard form factor. Systems based on the Intel Pentium 4 Processor in the 478-pin package comply with either:
- ATX specification (revision 2.01 or later)
- Using ATX form factor motherboards, we recommend a chassis that complies with ATX revision 2.01 or later.
- microATX specification (revision 1.0 or later)
- Using microATX form factor motherboards, we recommend a chassis that complies with microATX revision 1.0 or later.
The chassis must also support a lower internal ambient temperature than many standard ATX and microATX desktop chassis:
- Systems based on Intel Pentium 4 Processors 2.80 GHz (and below)
- Maintain internal chassis temperature at 40°C (or lower) for chassis in the maximum expected external ambient, typically 35°C.
- Systems based on Intel Pentium 4 Processors 3 GHz (and above)
- Maintain internal chassis temperature at 38°C (or lower) for chassis in the maximum expected external ambient, typically 35°C.
Chassis shipped with installed power supplies support either the ATX12V or SFX12V design guidelines.
Note | System integrators must use an ATX chassis specifically designed to support the boxed Intel Pentium 4 Processor in the 478-pin package. For more information, review the Integration Overview for Systems based on the boxed Intel Pentium 4 Processor in the 478-pin Package. Chassis designed to support the Intel Pentium 4 Processor in the 478-pin package ship with:
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