Boxed Processor Specifications
7.3.2
Variable Speed Fan
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 Figure 31 and Table 33,
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 Chapter 5) 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
Table 33 for the specific requirements.
Figure 31.
Boxed Processor Fan Heatsink Set Points
Higher Set Point
Highest Noise Level
Increasing Fan
Speed & Noise
Lower Set Point
Lowest Noise Level
X
Y
Z
Internal Chassis Temperature (Degrees C)
Table 33.
Fan Heatsink Power and Signal Specifications
Boxed Processor Fan
Heatsink Set Point (°C)
Boxed Processor Fan Speed
Notes
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
X ≤ 30
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.
Y = 35
-
-
When the internal chassis temperature is above or equal to
this set point, the fan operates at its highest speed.
Z ≥ 38
NOTES:
1. Set point variance is approximately ± 1 °C from fan heatsink to fan heatsink.
Datasheet
97
INTEL [ INTEL ]
