The boxed Intel® Pentium® 4
processor fan heatsink uses a high quality
variable speed fan. The variable speed fan allows
the processor to remain within its operating
thermal specifications by running at different
speeds over a short range of internal chassis
temperatures. This allows the fan to remain quiet
(i.e., fan is running at lowest speed and noise
level) for systems in normal operating
environments and to increase in speed, thereby
improving thermal efficiency, when external
temperature rises.
On the fan is a
thermister (thermal resistor), which monitors the
inlet air temperature (or the air temperature
entering the fan heatsink). As the inlet air
temperature increases, the fan speed (and noise
level) increases.
The fan operates at its lowest speed and noise
level until the inlet air temperature exceeds the
lower set point (approximately 36±1ºC*). The fan
speed and noise level will continue to increase
linearly until the inlet air temperature reaches
the higher set point (approximately 45±1ºC*). At
temperatures above the higher set point, the fan
will operate at its highest speed and noise
level.
System integrators should design systems that
ensure the air temperature around the boxed
Pentium 4 processor fan heatsink (or internal
chassis temperature) is kept below the lower set
point, for the lowest fan speed and noise level.
The recommended maximum internal chassis
temperature for boxed Intel Pentium 4
processor-based systems is 40ºC.
* Note: Set points may differ on various
boxed fan heatsinks due to processor
technology.
Please see the
Thermal Management document for details on
thermal requirements of the boxed Intel Pentium 4
processor. In addition, please refer the
Tested Chassis List for a listing of chassis
tested with the Intel® Desktop Board D850GB.
