# acpi_tz0:  _CRT value is absurd, ignored (-273.1C)



## usakhncit (Sep 23, 2019)

Hi
I have dualbooted FreeBSD (with Linux) on HP Pavilion G6 2298SE. This laptop has hybrid graphics card (intel and amd). The problem is that the system is giving me following error:

```
acpi_tz0:  _CRT value is absurd, ignored (-273.1C)
```
Please check attached screenshot.
Some forums' posts say to ignore this message, and some say to disable acpi. Moreover, I have noticed that in FreeBSD the AMD Graphics card is more active, as compared to Linux. Kindly guide me in this respect. Should I ignore it? Should I disable acpi? and Why AMD is more active in FreeBSD?
Thanks


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## SirDice (Sep 23, 2019)

Not guaranteed to solve the issue but have you checked for a BIOS/UEFI update for your laptop model?


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## usakhncit (Sep 23, 2019)

SirDice said:


> Not guaranteed to solve the issue but have you checked for a BIOS/UEFI update for your laptop model?


No, I did not checked or updated BIOS since the date of purchase in 2014. Because it is delicate matter and have danger of bios problems.


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## k.jacker (Sep 23, 2019)

Thermal zones, e.g. your _tz0_ are temperature sensors on the motherboard.
As far as I know there is no specification what they should be connected to.

A common place was a sensor under the CPU (in the socket) on older motherboards and also the northbridges often had temperature sensors close to them on the motherboard.
Today, sensors are build into the dies, throtteling/shutting down is not necessary anymore to be handled by acpi_thermal(4) as CPUs and Graphicscards do that on their own.

My 2014 notebook's only sensor is _tz0_ and it always shows around 25°C all the time. Stressing my CPU does not make it's temperature rise, so it seems to be connected to something else. Which is logical, as my Intel CPU has on-die sensor as most modern CPUs.
If you are concerned about CPU temperatures of your Intel CPU, load coretemp(4).



zetrotrack000 said:


> Should I ignore it?


Yes, there is nothing wrong whith your system, I'd guess there is a sensor defined in your BIOS (AML), but no sensor attached to it.


zetrotrack000 said:


> Should I disable acpi?


No.


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## Phishfry (Sep 24, 2019)

That particular number is a result of a conversion.
0 Kelvin = -273.1 Degrees Celsius
So what ACPI is reading is zero.
Meaning ignore this faulty reading





						How to convert Celsius to Kelvin (K)
					

Celsius to Kelvin formula - How to convert degrees Celsius to Kelvin (K)




					www.rapidtables.com


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## usakhncit (Sep 24, 2019)

Phishfry said:


> That particular number is a result of a conversion.
> 0 Kelvin = -273.1 Degrees Celsius
> So what ACPI is reading is zero.
> Meaning ignore this faulty reading
> ...


Can I disable this message?


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