How to check the cpu temperatures core by core

cpusensorstemperature

I have a Phenom X3-8450e which has a total of 3 cores. But when I ran "sensors" on a terminal I got this:

$ sensors
atk0110-acpi-0  
Adapter: ACPI interface  
Vcore Voltage:      +0.99 V  (min =  +0.85 V, max =  +1.60 V)  
+3.3 Voltage:      +3.38 V  (min =  +2.97 V, max =  +3.63 V)  
+5 Voltage:        +5.02 V  (min =  +4.50 V, max =  +5.50 V)  
+12 Voltage:      +11.98 V  (min = +10.20 V, max = +13.80 V)  
CPU FAN Speed:     1985 RPM  (min =  600 RPM, max = 7200 RPM)  
CHASSIS FAN Speed:    0 RPM  (min =  600 RPM, max = 7200 RPM)  
POWER FAN Speed:      0 RPM  (min =  600 RPM, max = 7200 RPM)  
CPU Temperature:    +32.0°C  (high = +60.0°C, crit = +95.0°C)  
MB Temperature:     +27.0°C  (high = +45.0°C, crit = +95.0°C)

As you can see it only displays a combined CPU Temperature: +32.0°C.

But how can I show the individual temperature of each core?

Best Answer

Use sensors-detect to configure the missing sensors, if they are available.

At my machine, there is a second sensor device handling the per-core sensors:

[...]
coretemp-isa-0000
Adapter: ISA adapter
Physical id 0:  +54.0°C  (high = +80.0°C, crit = +98.0°C)
Core 0:         +53.0°C  (high = +80.0°C, crit = +98.0°C)
Core 1:         +53.0°C  (high = +80.0°C, crit = +98.0°C)
Core 2:         +49.0°C  (high = +80.0°C, crit = +98.0°C)
Core 3:         +54.0°C  (high = +80.0°C, crit = +98.0°C)

i3status

Using i3status I believe you can change your configuration slightly so that it gets the CPU's core temperature directly from /sys by providing a path to its value. So change your rule to something like this:

order += "cpu_temperature 1"
# and more if you like...
# order += "cpu_temperature 2"

#...   
cpu_temperature 1 {
        format = "T: %degrees °C"
        path = "/sys/devices/platform/coretemp.0/temp1_input"
}

# cpu_temperature 2 {
#        format = "T: %degrees °C"
#        path = "/sys/devices/platform/coretemp.0/temp2_input"
# }

Here are 4 other ways to get your temp:

/proc

$ cat /proc/acpi/thermal_zone/THM0/temperature
temperature:             72 C

acpi

$ acpi -t
Thermal 0: ok, 64.0 degrees C

From the acpi man page:

   -t |  --thermal
             show thermal information

/sys

$ cat /sys/bus/acpi/devices/LNXTHERM\:01/thermal_zone/temp 
70000

lm_sensors

If you install the lmsensors package like so:

Fedora/CentOS/RHEL:

$ sudo yum install lm_sensors

Debian/Ubuntu:

$ sudo apt-get install lm-sensors

Detect your hardware:

$ sudo sensors-detect

You can also install the modules manually, for example:

$ sudo modprobe coretemp
$ modprobe i2c-i801

NOTE: The sensor-detect should detect your specific hardware, so you might need to modprobe <my driver> instead for the 2nd command above.

On my system I have the following i2c modules loaded:

$ lsmod | grep i2c
i2c_i801               11088  0 
i2c_algo_bit            5205  1 i915
i2c_core               27212  5 i2c_i801,i915,drm_kms_helper,drm,i2c_algo_bit

Now run the sensors app to query the resulting temperatures:

$ sudo sensors
acpitz-virtual-0
Adapter: Virtual device
temp1:        +68.0°C  (crit = +100.0°C)

thinkpad-isa-0000
Adapter: ISA adapter
fan1:        3831 RPM
temp1:        +68.0°C  
temp2:         +0.0°C  
temp3:         +0.0°C  
temp4:         +0.0°C  
temp5:         +0.0°C  
temp6:         +0.0°C  
temp7:         +0.0°C  
temp8:         +0.0°C  

coretemp-isa-0000
Adapter: ISA adapter
Core 0:       +56.0°C  (high = +95.0°C, crit = +105.0°C)

coretemp-isa-0002
Adapter: ISA adapter
Core 2:       +57.0°C  (high = +95.0°C, crit = +105.0°C)

This is on my Thinkpad T410 which has i5 M560. Here's one of the cores:

$ cat /proc/cpuinfo 
processor   : 0
vendor_id   : GenuineIntel
cpu family  : 6
model       : 37
model name  : Intel(R) Core(TM) i5 CPU       M 560  @ 2.67GHz
stepping    : 5
cpu MHz     : 1199.000
cache size  : 3072 KB
physical id : 0
siblings    : 4
core id     : 0
cpu cores   : 2
apicid      : 0
initial apicid  : 0
fpu     : yes
fpu_exception   : yes
cpuid level : 11
wp      : yes
flags       : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe syscall nx rdtscp lm constant_tsc arch_perfmon pebs bts rep_good xtopology nonstop_tsc aperfmperf pni pclmulqdq dtes64 monitor ds_cpl vmx smx est tm2 ssse3 cx16 xtpr pdcm sse4_1 sse4_2 popcnt aes lahf_lm ida arat tpr_shadow vnmi flexpriority ept vpid
bogomips    : 5319.22
clflush size    : 64
cache_alignment : 64
address sizes   : 36 bits physical, 48 bits virtual
power management:

CPU temperatures in linux: throttling or wrong reading

The difference is due to windows and linux using different CPU throttling profiles.

You do have some control over this on linux. For example, the following command will show you which profile is currently being used:

cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor

There are ways to choose which profiles to use. The Arch Linux wiki has good information on this, it may be worth a read:

CPU Frequency Scaling - Arch Wiki

There is an additional issue of fan control -- you need to make sure you have the proper drivers for controllin your fans and that they are set to a high enough speed when gaming.

Linux on Laptops can be a helpful resource.