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Intel
®
Core
TM
2 Duo E6400, E4300, and Intel
®
Pentium
®
Dual-Core E2160 Processor
October 2007
TDG
Order Number: 315279 -003US
39
Intel® Quiet System Technology (Intel® QST)—Intel
®
Core
TM
2 Duo E6400, E4300, and Intel
®
Pentium
®
Dual-Core E2160 Processor
6.1.1
Output Weighting Matrix
Intel QST provides an Output Weighting Matrix that provides a means for a single
thermal sensor to affect the speed of multiple fans. An example of how the matrix
could be used is if a sensor located next to the memory is sensitive to changes in both
the processor heatsink fan and a second fan in the system. By placing a factor in this
matrix additional the Intel QST could command the processor thermal solution fan and
this second fan to both accelerate a small amount. At the system level these two small
changes can result in a smaller change in acoustics than having a single fan respond to
this sensor.
6.1.2
Proportional-Integral-Derivative (PID)
The use of Proportional-Integral-Derivative (PID) control algorithms allow the
magnitude of fan response to be determined based upon the difference between
current temperature readings and specific temperature targets. A major advantage of a
PID Algorithm is the ability to control the fans to achieve sensor temperatures much
closer to the T
CONTROL
.
Figure 14
is an illustration of the PID fan control algorithm. As illustrated in the figure,
when the actual temperature is below the target temperature, the fan will slow down.
The current FSC devices have a fixed temperature vs. PWM output relationship and
miss this opportunity to achieve additional acoustic benefits. As the actual temperature
starts ramping up and approaches the target temperature, the algorithm will instruct
the fan to speed up gradually, but will not abruptly increase the fan speed to respond to
the condition. It can allow an overshoot over the target temperature for a short period
of time while ramping up the fan to bring the actual temperature to the target
temperature. As a result of its operation, the PID control algorithm can enable an
acoustic-friendly platform.
Figure 13.
Intel® QST Overview
Fan to sensor
Relationship
(Output Weighting Matrix)
Temperature sensing
and response
Calculations
(PID)
Fan Commands
(PID)
Fans
Temperature
Sensors
Intel
®
QST
System Response
PWM
PECI / SST