Core temperature

Pietro Cerutti gahr at
Fri Aug 10 03:50:49 PDT 2007

Dag-Erling Smørgrav wrote:
> I've written a quick-and-dirty driver for the built-in digital
> temperature sensor in Intel's Core and Core 2 CPUs (and Xeons built on
> the Core architecture).  The driver exports four sysctl nodes under
> hw.coretemp:
>   hw.coretemp.tjmax     Maximum core temperature (currently hardcoded
>                         To 100°C, may actually be 85°C on some systems)
>     current temperature in °C below Tj(max)
>   hw.coretemp.interrupt Lower 32 bits of the IA32_THERMAL_INTERRUPT MSR
>   hw.coretemp.status    Lower 32 bits of the IA32_THERMAL_STATUS MSR
> I intend to move these into dev.cpu.N in a later version.
> Note that the driver currently makes no attempt to handle multi-CPU
> systems; it will simply report the temperature of the CPU that contains
> whichever core the requesting process happens to be running on.

Hi Des,
thanks a lot!

Could you please try to explain these results?

> sysctl hw.coretemp.tjmax hw.acpi.thermal.tz0.temperature
hw.coretemp.tjmax: 100 -38
hw.acpi.thermal.tz0.temperature: 66.8C

Shouldn't be (hw.coretemp.tjmax -



Pietro Cerutti

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