All Pentium® 4 processor-based systems require heat sinks with fans. Boxed Pentium 4 processors are usually shipped with a high-quality variable speed fan heat sink, which can effectively transfer processor heat to the system air, allowing the processor to remain within its operating thermal specifications. If not, you can get a heat sink and fan specifically rated for your processor.
The variable speed Pentium 4 processor fan operates at a low speed while internal chassis temperatures are low. If internal chassis temperatures increase beyond a lower set point, the fan speed will rise linearly with the internal chassis temperature until the higher set point is reached. As fan speed increases, so does the noise that the fan generates. Systems should be designed to provide air around the boxed processor fan heat sink that remains below the lower set point.
Since moving heat to the system air is only half the task, sufficient system airflow is also needed in order to exhaust the warm air. Without a steady stream of air through the system, the fan heat sink will re-circulate warm air, and therefore may not cool the processor adequately.
Installing the fan heatsink
The fan heatsink included with the boxed Pentium 4 processor must be securely attached to the processor. Thermal interface material (either attached to the bottom of the fan heat sink or applied during system integration with an applicator) provides effective heat transfer from the processor to the fan heat sink.
The fan cable provides power to the fan by connecting to a motherboard-mounted power header and also allows the fan to provide fan speed information to the motherboard. Only motherboards with hardware monitoring circuitry can use the fan speed signal. Refer to your system board manual for the location of the power header.
Thermal Interface Material
Thermal interface material is required for proper heat transfer from the processor to the heat sink. Boxed Pentium 4 processors will either have thermal interface material attached to the bottom of the fan heat sink or come with thermal interface material and an applicator.
Intel does not recommend the removal of the thermal interface material located on the bottom of the boxed processor fan heat sink. Removal of this material may cause damage to the processor and will void the boxed processor warranty. If you remove and re-use the heat sink, you will need to replace the thermal interface material.