521 datasheet(95/96 Pages) INTEL

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Datasheet

Boxed Processor Specifications

7.3.2

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

Figure 7-9 and Table 7-2, 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 7-1 for the specific

requirements.

Figure 7-9. Boxed Processor Fan Heatsink Set Points

Lower Set Point

Lowest Noise Level

Internal Chassis Temperature (Degrees C)

Increasing Fan

Speed & Noise

Higher Set Point

Highest Noise Level

521 Datasheet(PDF) 95 Page - Intel Corporation