Intel 4 620 JM80547PG0722MM Data Sheet

96

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 internal chassis 
temperatures. This allows the processor fan to operate at a lower speed and noise level, while 
internal chassis temperatures are low. If the internal chassis temperature increases beyond a 
lower set point, the fan speed will rise linearly with the internal 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. Systems should be designed to provide adequate air around the boxed 
processor fan heatsink that remains cooler than the lower set point. These set points, 
represented in 

, can vary by a few degrees from fan heatsink to fan 

heatsink. 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.

Lower Set Point

Lowest Noise Level

Internal Chassis Temperature (Degrees C)

X

Y

Z

Increasing Fan
Speed & Noise

Higher Set Point

Highest Noise Level