Variable Speed Fan; Boxed Processor Fan Heatsink Set Points; Fan Heatsink Power And Signal Specifications - Intel Q9300 - Core 2 Quad 2.5 GHz 6M L2 Cache 1333MHz FSB LGA775 Quad-Core Processor Datasheet

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
and Table
internal chassis temperature should be kept below 38 ºC. Meeting the processor's
temperature specification (see
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 7-1
Figure 7-9.

Boxed Processor Fan Heatsink Set Points

Table 7-2.

Fan Heatsink Power and Signal Specifications

Boxed Processor
Fan Heatsink Set
Point (°C)
X ≤ 30
Y = 35
Z ≥ 39
NOTES:
1. Set point variance is approximately ±1 °C from fan heatsink to fan heatsink.
100
7-2, can vary by a few degrees from fan heatsink to fan heatsink. The
Chapter
for the specific requirements.
Lower Set Point
Lowest Noise Level
X
Internal Chassis Temperature (Degrees C)
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.
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.
When the internal chassis temperature is above or equal to this
set point, the fan operates at its highest speed.
5) is the responsibility of the system
Increasing Fan
Speed & Noise
Y
Boxed Processor Fan Speed
Boxed Processor Specifications
Figure 7-9
Higher Set Point
Highest Noise Level
Z
Notes
Datasheet
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