[lm-sensors] voltage reading too low: what next?

[lm-sensors] voltage reading too low: what next?

[James Kirkpatrick]

    Hi,

I have just finished building a computer at uni. It has two dual core 
Opterons 275 on an MSI K8N-DL. It is very hot in my town at the moment 
and I would like to monitor temperature etc.

I *think* that sensors-detect is running all fine, the output I get from 
`sensors` is:

<quote>
w83627thf-isa-0290
Adapter: ISA adapter
VCore:     +1.02 V  (min =  +0.94 V, max =  +0.96 V)
+12V:      +4.13 V  (min = +10.82 V, max = +13.19 V)
+3.3V:     +1.92 V  (min =  +3.14 V, max =  +3.47 V)
+5V:       +5.04 V  (min =  +4.75 V, max =  +5.25 V)
-12V:     -14.91 V  (min = -10.80 V, max = -13.18 V)
V5SB:      +5.08 V  (min =  +4.76 V, max =  +5.24 V)
VBat:      +2.93 V  (min =  +2.40 V, max =  +3.60 V)
fan1:     5578 RPM  (min = 9375 RPM, div = 2)
CPU Fan:  5769 RPM  (min =   -1 RPM, div = 2)
fan3:        0 RPM  (min = 112500 RPM, div = 2)
M/B Temp:    +47 C  (high =    +5 C, hyst =    +0 C)   sensor = thermistor
CPU Temp:  +42.0 C  (high =   +80 C, hyst =   +75 C)   sensor = thermistor
temp3:     +39.0 C  (high =   +80 C, hyst =   +75 C)   sensor = thermistor
vid:      +0.275 V  (VRM Version 9.0)
alarms:
beep_enable:
          Sound alarm disabled

eeprom-i2c-0-53
Adapter: SMBus nForce2 adapter at f800
Memory type:            DDR SDRAM DIMM
Memory size (MB):       1024

eeprom-i2c-0-52
Adapter: SMBus nForce2 adapter at f800
Memory type:            DDR SDRAM DIMM
Memory size (MB):       1024

eeprom-i2c-0-51
Adapter: SMBus nForce2 adapter at f800
Memory type:            DDR SDRAM DIMM
Memory size (MB):       1024

eeprom-i2c-0-50
Adapter: SMBus nForce2 adapter at f800
Memory type:            DDR SDRAM DIMM
Memory size (MB):       1024

<\quote>


This suggest that the rail which ought to have 3.3V, provides only 1.9! 
Does anyone have any information about whether this is a real 
problem/artifact? What's my next step?

Thanks for any advice and for bearing with my ignorance!
James

[lm-sensors] voltage reading too low: what next?

[Rudolf Marek]

Hi James,

> <quote>
> w83627thf-isa-0290
> Adapter: ISA adapter
> VCore:     +1.02 V  (min =  +0.94 V, max =  +0.96 V)
> +12V:      +4.13 V  (min = +10.82 V, max = +13.19 V)
> +3.3V:     +1.92 V  (min =  +3.14 V, max =  +3.47 V)

Well how the inputs are connected knows only the MSI. They may have used
different scaling factors. This is the reason why you see this value.

> +5V:       +5.04 V  (min =  +4.75 V, max =  +5.25 V)
> -12V:     -14.91 V  (min = -10.80 V, max = -13.18 V)
> V5SB:      +5.08 V  (min =  +4.76 V, max =  +5.24 V)
> VBat:      +2.93 V  (min =  +2.40 V, max =  +3.60 V)
> fan1:     5578 RPM  (min = 9375 RPM, div = 2)
> CPU Fan:  5769 RPM  (min =   -1 RPM, div = 2)
> fan3:        0 RPM  (min = 112500 RPM, div = 2)
> M/B Temp:    +47 C  (high =    +5 C, hyst =    +0 C)   sensor = thermistor
> CPU Temp:  +42.0 C  (high =   +80 C, hyst =   +75 C)   sensor = thermistor
> temp3:     +39.0 C  (high =   +80 C, hyst =   +75 C)   sensor = thermistor
> vid:      +0.275 V  (VRM Version 9.0)

All in all if you want to know what MSI did please ask them what scaling
resistors they used for the ADC voltage inputs of w83627thf chip on this
motherboard.

The CPU has not 42C (even if it is nice value and the ultimate answer) because
it is the temperature under the CPU rather inside. I implemented a driver that
reads the CPU temp from the CPU. Hopefully it will be in 2.6.19. You may find it
here:
http://assembler.cz/download/amd_digital_temp.tar.gz

I hope it helps,
Regards
Rudolf