Core temperature

Dag-Erling Smørgrav des at
Thu Aug 9 16:18:45 PDT 2007

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.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.

Dag-Erling Smørgrav - des at

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