[lm-sensors] Wrong CPU Temp

[Jean Delvare]

Hi Paul,

On Thu, 12 Jun 2008 14:13:50 +0100, Paul Smith wrote:
> In the output below, the value
> 
> CPU Temp:     -2.0°C  (low  = +127.0°C, high = +127.0°C)  sensor = transistor
> 
> seems unlikely:
> 
> $ sensors
> it8712-isa-0290
> Adapter: ISA adapter
> VCore 1:     +1.28 V  (min =  +0.00 V, max =  +4.08 V)
> VCore 2:     +1.82 V  (min =  +0.00 V, max =  +4.08 V)
> +3.3V:       +3.38 V  (min =  +0.00 V, max =  +4.08 V)
> +5V:         +6.85 V  (min =  +0.00 V, max =  +6.85 V)   ALARM
> +12V:       +11.84 V  (min =  +0.00 V, max = +16.32 V)
> -12V:       -13.86 V  (min = -27.36 V, max =  +3.93 V)
> -5V:         -7.34 V  (min = -13.64 V, max =  +4.03 V)
> Stdby:       +6.85 V  (min =  +0.00 V, max =  +6.85 V)   ALARM
> VBat:        +4.08 V
> fan1:       1704 RPM  (min =    0 RPM, div = 8)
> fan2:          0 RPM  (min =    0 RPM, div = 8)
> fan3:          0 RPM  (min =    0 RPM, div = 8)
> M/B Temp:    -55.0°C  (low  = +127.0°C, high = +127.0°C)  sensor = transistor
> CPU Temp:     -2.0°C  (low  = +127.0°C, high = +127.0°C)  sensor = transistor
> Temp3:       +47.0°C  (low  = +127.0°C, high = +90.0°C)  sensor = thermal diode
> cpu0_vid:   +1.350 V
> 
> $
> 
> My motherboard is a GigaBite GA-81945PL-G, the processor is an Intel
> Dual Core, and the operating system is Fedora 9.
> 
> Any ideas?

Typical of Gigabyte boards. They put two Ethernet chips, 2 USB
controllers, Firewire, two Serial ATA controllers, etc. on the board,
but omit the thermistor for motherboard temperature to save a few
cents. Go figure... My own board (Gigabyte K8V Ultra-939) says:

temp1:       +25.0°C  (low  = +127.0°C, high = +127.0°C)  sensor = disabled
temp2:       -55.0°C  (low  = +127.0°C, high = +127.0°C)  sensor = disabled
temp3:       +47.0°C  (low  = +10.0°C, high = +51.0°C)  sensor = thermal diode

And temp1 never changes. So, same as yours: temp3 is the CPU
temperature, and temp1 and temp2 can be ignored (and even disabled).
The relevant part of my configuration file is:

### Temperatures

   # Gigabyte confirmed that there is no system temperature sensor on this
   # motherboard. This is really disappointing, as the board is otherwise
   # full featured.

   ignore temp1
   ignore temp2
   label  temp3  "CPU Temp"

   set temp1_type 0
   set temp2_type 0

   # The CPU temperature was seen from 34 to 48 degrees C so far.
   set temp3_min  10
   set temp3_max  51

Hope that helps,
-- 
Jean Delvare