Intel Pentium D 830 HH80551PG0802MN Data Sheet

95

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 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 then 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 39 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.

º

X 

≤ 30

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 = 35

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 

≥ 39

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