how to check the cpu temperature ?

[Maaz]

its a dual core(Core Duo) machine

I am trying to check the CPU temp
# ls /proc/acpi/thermal_zone/TZ
TZ0 TZ1 TZ2 TZ3 TZ4

why 4 directories ? this machine only have 2 cpu cores... I think there should be only 2 directories i.e TZ1 and TZ2 .. am I right ?

# cat /proc/acpi/thermal_zone/TZ1/temperature
temperature: 51 C
# cat /proc/acpi/thermal_zone/TZ2/temperature
temperature: 47 C
# cat /proc/acpi/thermal_zone/TZ3/temperature
temperature: 37 C
# cat /proc/acpi/thermal_zone/TZ4/temperature
temperature: 50 C

and why the difference b/w temperatures
TZ1/temperature is 51 C
TZ2/temperature is 47 C
TZ3/temperature is 37 C
TZ4/temperature is 50 C

Regards
Maaz

[Matti_Kurkela · Accepted solution]

According to Intel documentation, when the designers ran the Core Duo processor design in the simulator, they found several possible "hot spots" in the design.

With the older processors, it was possible to locate a single "hottest spot" of the processor, and calibrate the thermal sensor for it. But in Core Duo designs, the location of the hottest spot depends on the combined workload of both cores. So the designer placed more sensors to cover multiple possible hot spots.

http://www.intel.com/technology/itj/2006/volume10issue02/art03_Power_and_Thermal_Management/p03_power_management.htm

I could not quickly find a document that would describe the sensor locations in detail. Intel's website has a lot of documentation on their CPUs: if you are interested, I would suggest searching there.

MK

[mohamed.bouraoui]

Dear friend,
in linux system, the kernel look the cpu with core duo like 2 cpus. it's not a bug but just like that.
the diff bw temprator cpu it's related with the core activitys.
you can look that with command top.
thx.

[MarkSeger]

If your platform supports ipmi, and most do, you can use the command "ipmitool sdr". For example, on a dl145 you see output like:

CPU0 TEMP | 46 degrees C | ok
CPU1 TEMP | 43 degrees C | ok
SYS TEMP | 26 degrees C | ok

on a dl160g5 you'll see:

CPU0 Dmn 0 Temp,48,degrees C,ok
CPU0 Dmn 1 Temp,13,degrees C,ok
CPU1 Dmn 0 Temp,51,degrees C,ok
CPU1 Dmn 1 Temp,17,degrees C,ok

and other others like a bl460 you'd see:

Temp 1 | 46 degrees C | ok
Temp 2 | 33 degrees C | ok
Temp 3 | 30 degrees C | ok
Temp 4 | 30 degrees C | ok
Temp 5 | 31 degrees C | ok
Temp 6 | 30 degrees C | ok
Temp 7 | 30 degrees C | ok
Temp 8 | 65 degrees C | ok
Temp 9 | 19 degrees C | ok

which doesn't really tell you where the sensors are. In any event you can either do this manually or run collectl and it will log the data for you taking a sample every 2 minutes, which of course you can change if you prefer to look at them more/less frequently.

-mark