Intel Pentium 4 Processor in the 478-PinPackage at 1.40 GHz, 1.50 GHz, 1.60 GHz, 1.70 GHz, 1.80 GHz, 1.90 GHz, and 2GHz

Boxed Processor Specifications
92 Datasheet
8.4.1 Boxed Processor Cooling Requirements
The boxed processor may be directly cooled with a fan heatsink. However, meeting the
processor's temperature specification is also function of the thermal design of the entire
system, and ultimately the responsibility of the system integrator. The processor
temperature specification is found in Chapter 6.0 of this document. The boxed processor
fan heatsink is able to keep the processor temperature within the specifications (see Table
33) in chassis that provide good thermal management. For the boxed processor fan
heatsink to operate properly, it is critical that the airflow provided to the fan heatsink is
unimpeded. Airflow of the fan heatsink is into the center and out of the sides of the fan
heatsink. Airspace is required around the fan to ensure that the airflow through the fan
heatsink is not blocked. Blocking the airflow to the fan heatsink reduces the cooling
efficiency and decreases fan life. Figure 37 and Figure 38 illustrate an acceptable
airspace clearance for the fan heatsink. The air temperature entering the fan should be
kept below 40°C. Again, meeting the processor's temperature specification is the
responsibility of the system integrator.
Figure 37. Boxed Processor Fan Heatsink Airspace Keepout Requirements (side 1 view)