Re: SSD temperature discrepancies?

Yrrah wrote:
> x-post: alt.comp.hardware,alt.os.linux
> 
> ssd temperature discrepancies:
> 
> smartctl: 29 C
> hddtemp: 29 C
> -
> (Gnome-)Disks: 99 C
> Psensor: 99 C
> 
> 29 C is correct. But why the 99 C?
> Disks and Psensor show the correct tempeatures of the other disks (HD
> & SSD).
> 
> Yrrah

There's a crazy assertion here.

https://steamcommunity.com/app/221410/discussions/0/3726075043714056809/

   "You need to run lm-sensors once.

    https://wiki.ubuntuusers.de/Lm_sensors/
   "

A superstition of some sort ? I can't see how
that could fix a "SMART passing to some other subsystem"
issue. It's true that LMsensors measures some temps
using the hardware monitor on the SuperIO, but the
SSDs are measured on the SSD and the info populates
the SMART table.

SMART is full of quirks. And to start with, the SMART table
for SSDs is different than the SMART table for HDDs. The interpretation
of the tables is not necessarily "standard". And this means
a lot of if/then/else in some readout code. There are SMART fields
on disks, where we don't know what they do.

https://en.wikipedia.org/wiki/S.M.A.R.T.

    "As manufacturers do not necessarily agree on precise attribute
     definitions and measurement units, the following list of attributes
     is a general guide only."

     190
     0xBE   Temperature Difference or Airflow Temperature

            Value is equal to (100-temp. °C), allowing manufacturer to set
            a minimum threshold which corresponds to a maximum temperature.
            This also follows the convention of 100 being a best-case value
            and lower values being undesirable. However, some older drives
            may instead report raw Temperature (identical to 0xC2) or
            Temperature minus 50 here.

     194
     0xC2   Temperature or Temperature Celsius

            Indicates the device temperature,
            if the appropriate sensor is fitted [thermistor on PCB etc]

Have smartctl dump the entire table, and maybe you can
spot the 99 in there.

You might need to use the SSD drive Make and Model number
to Google for "SMART quirks" for it.

    Paul