Intel W3530 AT80601000897AB User Manual

Product codes
AT80601000897AB
Page of 106
Boxed Processor Specifications
106
Intel® Xeon® Processor 3500 Series Datasheet Volume 1 
If the boxed processor fan heatsink 4-pin connector is connected to a 4-pin 
motherboard header and the motherboard is designed with a fan speed controller with 
PWM output (CONTROL see 
) and remote thermal diode measurement 
capability the boxed processor will operate as follows:
As processor power has increased the required thermal solutions have generated 
increasingly more noise. Intel has added an option to the boxed processor that allows 
system integrators to have a quieter system in the most common usage.
The 4th wire PWM solution provides better control over chassis acoustics. This is 
achieved by more accurate measurement of processor die temperature through the 
processor's Digital Thermal Sensors (DTS) and PECI. Fan RPM is modulated through the 
use of an ASIC located on the motherboard that sends out a PWM control signal to the 
4th pin of the connector labeled as CONTROL. The fan speed is based on actual 
processor temperature instead of internal ambient chassis temperatures.
If the new 4-pin active fan heat sink solution is connected to an older 3-pin baseboard 
processor fan header it will default back to a thermistor controlled. Under thermistor 
controlled mode, the fan RPM is automatically varied based on the Tinlet temperature 
measured by a thermistor located at the fan inlet.
For more details on specific motherboard requirements for 4-wire based fan speed 
control, see the appropriate processor Thermal and Mechanical Design Guidelines (see 
).
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