[lm-sensors] About fancontrol: I could not control the CPU fan speed

Christian Mahr christian.mahr.ulm at arcor.de
Sat Nov 4 11:30:08 CET 2006


Hi Yonkui,

-is this a 3 or 4 pin fan?
-is this a 3 or 4 pin connector on MB?

when you operate pwm1 manually, 
- can you see the value with cat pwm1 you did write ther before?
- are you sure to be in manual mode pwm_enable=1 ?
- what do the other pwm1* register read?

Christian

Am Samstag, 4. November 2006 04:34 schrieb Yongkui Han:
> HI,
>
> Could anybody help me with this, or point me to somewhere?
>
> Thanks!
>
> Thanks.
> Yongkui
>
> On 10/30/06, Yongkui Han <hanyongkui99 at gmail.com> wrote:
> > 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
> > (87.8oF). 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 (
> > 114.8oF). 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 spee d.
> > >
> > > 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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