Jtdcftul

I'm running sensors-detect on my system with lm-sensors because my system keep shutting down when I watch youtube videos

So I'm wondering how can I find the temperatures of the fan and cpu manually without a 3rd party software like lm-sensors? I'm just not sure where they're stored.

processor   : 0

vendor_id   : AuthenticAMD

cpu family  : 16

model       : 6

model name  : AMD Athlon(tm) II X2 240e Processor

power management: ts ttp tm stc 100mhzsteps hwpstate

x86_64

It sounds like what you want is /sys/class/hwmon and /sys/class/thermal.

Both of these provide simple shell based access to the data you want (the hwmon directory will also include other sensor types). Each has one directory for each sensor interface in your system (which may have more than one sensor).

Three other things to note though:

• Unless you have a really bad system, running the sensors command even once a second shouldn't have any percievable effect. In fact, regularly reading the files in the above mentioned directories may have more of an effect.


• Graphs are your friend here. I would suggest getting something like netdata or collectd running so you have realtime (or near realtime) data to look at.


• Check your voltages too. What your describing could also be due to having a power supply that can't keep up with your system's power requirements. This will be indicated by voltages dropping significantly when the system is under high load.

This answer is about one way to monitor processor temperature manually for some Intel processors via accessing the Machine Specific Registers (MSR) directly.

The first thing to note is, in this case, what is read out of the MSR is relative to the Tcc, the limit temperature, so an additional calculation is required to determine the actual temperature.

Refer to the Intel® 64 and IA-32 Architectures Software Developer’s Manual, or in your case the AMD equivalent.

In my case, I want bits 22-16 of the MSR at 0x1B1, aka IA32_PACKAGE_THERM_STATUS. The Tcc for my older i7-2600K is 98 degrees.

Here is a simple script to monitor the temperature (and CPU frequency) manually:

#! /bin/dash

#

# temp_mon3 Smythies 2016.10.05

#       a simplified version of temp_mon2,

#       for monitoring temp.

#       Note: it is on purpose that -a is not used.

#       Also CPU0 frequency (1 is good enough, when all

#       are loaded).

#

# temp_mon2 Smythies 2016.09.29

#       Monitor Package temperatures.

#       Use clock modulation to control temps.

#       i.e. simulate the second to last level

#       of defense.

#       Use simple primatives.

#       run as sudo

#       hardcoded for my tcc of 98 degrees.

#

echo ... begin package temperature monitoring ...



#

# In case I forgot (which I often do)



modprobe msr



#

# first let the drastic effect of the sudo command decay

# Done later in temp_mon3.



#

# some stuff



COMMAND="rdmsr --bitfield 22:16 -u 0x1B1"

COMMAND2="cat /sys/devices/system/cpu/cpufreq/policy0/scaling_cur_freq"



#

# then get on with it



while [ 1 ];do

  sleep 4

  TEMP_RAW=$(eval $COMMAND)

  CPU0_FREQ=$(eval $COMMAND2)

  TEMP_ACT=$((98-TEMP_RAW))

  echo "$TEMP_ACT   $CPU0_FREQ"

done

And here is some sample output, where I add some CPU load after awhile (temp goes from 31 to 73 degrees):

$ sudo ./temp_mon3

[sudo] password for doug:

... begin package temperature monitoring ...

31   1605275

31   1605154

32   1605164

30   1605148

31   1605176

51   3511279

54   3511278

55   3511279

57   3511283

58   3511279

60   3511278

61   3511284

63   3511279

64   3511280

64   3511280

66   3511280

67   3511278

68   3511280

68   3511281

69   3511278

71   3511280

70   3511281

71   3511281

71   3511280

72   3511276

72   3511277

73   3511283

73   3511279

^C

I don't know what you really want. The lm-sensor program (and therefore the sensors command) make use of the libsensor library; in case you use Ubuntu 18.04 it is libsensors4, version 3.4.0-4. This is the same library which reads the temperature as can be seen in the sysdirectory.

To sum it up, sensors is a good choice. To watch the temperature continuously use

watch -n 1 sensors

If you want to write a program, you have to take a look at libsensors with man libsensorsor take a look in the /usr/share/doc/. You have to include #include <sensors/sensors.h>. It will use the sensors.conffiles /etc/sensors3.conf and/or /etc/sensors.conf. Further (users) configuration can be found in /etc/sensors.d/, if used.

If you think that you are missing some sensors take a look at the /sys/class/thermal or the linked /sys/devices/virtual/thermal directory.

To get the temperatures of the all thermal zones use

$ cat /sys/devices/virtual/thermal/thermal_zone?/temp



77000

66000

67000

The temperature is measured in miliCelcius (mC), in the case above 77.0, 66.0, 67,0 °C.

To watch continously use

watch -n 1 cat /sys/devices/virtual/thermal/thermal_zone?/temp

In this directory you can also find information about your cooling (fan) devices, and how the PID regulators are programmed.

I would also like to state that some overtemperature protection is coded very hardware based (this is a good idea), where the data is placed in your bios.