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List:       lm-sensors
Subject:    [lm-sensors] About fancontrol: I could not control the CPU fan
From:       hanyongkui99 () gmail ! com (Yongkui Han)
Date:       2006-10-31 3:51:10
Message-ID: 2ca62ec0610301951x37d0271fo4e6595d330a25d5b () mail ! gmail ! com
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Hi All,

I just found the following information on page 43 of the motherboard manual.
ftp://download.intel.com/design/motherbd/mv/A6514501.pdf

--------------------------
1.14.2.2 Fan Connectors
The D850MD and D850MV boards have two fan connectors with thermal control
signals (fan 1
and fan 2) that are used to switch the fans on and off as determined by the
thermal sensors.
The ambient temperature of a D850MD- or D850MV-based system is thermally
monitored by
separate temperature sensors that control voltage to the fan 1 and fan 2
connectors. If the fans
attached to these connectors provide a tachometer signal, the sensor reports
the fan speed to the hardware monitor component.
The temperature sensors that control the fans are initialized by the BIOS at
power-up to turn on only when the sensor reaches 36 oC (96.8 oF). The fans
switch off when their respective sensors cool down to 31 oC (87.8 oF). This
prevents the fans from turning off and on when the ambient air around the
sensor fluctuates around 35?36 oC. When the fans switch on, they may appear
to rotate slowly because the fan's duty cycle starts at 70 percent and rises
to 100 percent when the sensor reaches 46 oC (114.8 oF).
Table 12 summarizes the functions of the four fan connectors.
Table 12. Fan Connector Descriptions

Feature                          Processor Fan       Fan 1
 Fan 2                       Fan 3
+12 V DC connection       Yes                      Yes
Yes                         Yes
Tachometer output           Yes                      No
Yes                         No
Controllable                     No
Yes                    Yes                         Yes
----------------------------

In the Table 12, It says the Processor Fan is not controllable, although the
other fans are controllable.

So this means that I cannot control the CPU fan speed. But it seems that we
could do some tricks to make the system think the thermal sensor is higher
than 46C. Then the CPU fan speed should run at full speed. Then this is what
I want, a fixed CPU fan speed.

Any suggestions?

Thanks!
Yongkui



On 10/30/06, Yongkui Han <hanyongkui99 at gmail.com > wrote:
>
> Hi All,
>
> I am trying to control the speed of the CPU fan.  I would like to set
> constant CPU fan speed.
>
> My CPU fan is Intel Fan & Heatsink A65061-001, with 3 wires, green,
> yellow, and black.
>
> I run pwmconfig to see /sys/bus/i2c/devices/9191-0800/pwm1 is controling
> fan1_input, which is the CPU fan, and saved the default configuration into
> /etc/fancontrol file. The pwmconfig command didn't report any errors but I
> noticed that when it reports the CPU fan speed of 0, the CPU fan is actually
> still running. Also, the GNUPLOT graph of the correlation between PWM and
> Fan Speed is very strange. The fan speed are 3233 for all PWM values 2--255,
> and the fan speed is 0 for PWM=0. This is very weird.  The pdf file
> pwmtest.pdf is enclosed for your reference.
>
> Then I run fancontrol command. the command is running correctly without
> reporting errors. Now the sensors command will only report a fan speed of 0
> RPM. But the problem is the CPU fan is still running, it never stops at all.
>
>
> I also tried not to use fancontrol. I use the command: echo 64 >
> /sys/bus/i2c/devices/9191-0800/pwm1, but still this had no effect on the
> CPU fan speed.
>
> Could some one help me with the CPU fan speed control?
>
> Thanks!
>
> BTW,
> I have an Intel D850MV motherboard. There is an ADM1025A sensor chip on
> the motherboard. Also there is an LPC47M142-NC Super I/O chip on the
> motherboard. My CPU is a Pentium 4 CPU, 1.7GHz.
>
> The following is a sample output for my lm-sensors software.
> ---------------------------------
> $ sensors
> adm1025-i2c-0-2d
> Adapter: SMBus I801 adapter at efa0
>
> +2.5V:     +2.49 V  (min =  +2.25 V, max =  +2.75 V)
> VCore:     +1.68 V  (min =  +1.66 V, max =  +1.84 V)
> +3.3V:     +3.30 V  (min =  +2.97 V, max =  +3.63 V)
> +5V:       +5.13 V  (min =  +4.50 V, max =  +5.50 V)
> VCC:       +3.30 V  (min =  +2.97 V, max =  +3.63 V)
> CPU Temp:  +35.0?C  (low  =   +10?C, high =   +60?C)
> M/B Temp:  +34.0?C  (low  =   +10?C, high =   +45?C)
> vid:      +1.750 V  (VRM Version 9.0)
>
> smsc47m1-isa-0800
> Adapter: ISA adapter
> fan1:     3233 RPM  (min =  640 RPM, div = 8)
> fan2:        0 RPM  (min =  640 RPM, div = 8)
> --------------------------------------------------------------
>
>
> Regards,
> Yongkui
>
>
>
>
>
>
>
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