Intel 4 620 JM80547PG0722MM Data Sheet

104

If the boxed processor fan heatsink 4-pin connector is connected to a 3-pin motherboard header, it 
will operate as follows:

The boxed processor fan will operate at different speeds over a short range of temperatures 
based on a thermistor located in the fan hub area. This allows the boxed processor fan to 
operate at a lower speed and noise level while thermistor temperatures are low. If the 
thermistor senses a temperatures increase beyond a lower set point, the fan speed will rise 
linearly with the temperature until the higher set point is reached. At that point, the fan speed is 
at its maximum. As fan speed increases, so does fan noise levels. These set points are 
represented in 

. The internal chassis temperature should be kept below 

38 ºC. Meeting the processor’s temperature specification (see 

) is the responsibility 

of the system integrator. 

The motherboard must supply a constant +12 V to the processor’s power header to ensure proper 
operation of the variable speed fan for the boxed processor (refer to 

) for the specific 

requirements. 

X 

≤ 23

When the internal chassis temperature is below or equal to this set point, 
the fan operates at its lowest speed. Recommended maximum internal 
chassis temperature for nominal operating environment.

1

1.

Set point variance is approximately ±1 °C from fan heatsink to fan heatsink.

Y = 29

When the internal chassis temperature is at this point, the fan operates 
between its lowest and highest speeds. Recommended maximum 
internal chassis temperature for worst-case operating environment.

 Z 

≥ 35

When the internal chassis temperature is above or equal to this set point, 
the fan operates at its highest speed.

Lower Set Point

Lowest Noise Level

Internal Chassis Temperature (Degrees C)

X

Y

Z

Increasing Fan
Speed & Noise

Higher Set Point

Highest Noise Level