Variable Speed Fan; Boxed Processor Fan Heatsink Set Points - Intel E3300 Datasheet

Boxed Processor Specifications
7.4.2

Variable Speed Fan

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
to fan heatsink. The internal chassis temperature should be kept below 38 ºC.
Meeting the processor's temperature specification (see
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
Table 29
Figure 26.

Boxed Processor Fan Heatsink Set Points

Datasheet
Figure 26 and
for the specific requirements.
Lower Set Point
Lowest Noise Level
X
Internal Chassis Temperature (Degrees C)
Table 30, can vary by a few degrees from fan heatsink
Increasing Fan
Speed & Noise
Y
Chapter 5) is the
Higher Set Point
Highest Noise Level
Z
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