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InvisibleShadowGhost
Asked: 2018-08-11 11:45:43 +0800 CST

Cpufrequtils available frequencies

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/etc/init.d/cpufrequtils has the following comment

 and which limits to set. Both MIN_SPEED and MAX_SPEED must be values
 listed in:
   cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_available_frequencies
 a value of 0 for any of the two variables will disabling the use of 
 that limit variable.

But the file /sys/devices/system/cpu/cpu0/cpufreq/scaling_available_frequencies does not exist for me? Do you have it? Where could I get a fitting frequency?

Best regards

cpu

1 Answers

  1. Best Answer

    Intel has stopped publishing available frequencies but you can approximate what they are:

    Use these commands to see available steps and min/max:

    $ cd /sys/devices/system/cpu/intel_pstate
$ paste <(ls *) <(cat *) | column -s $'\t' -t
max_perf_pct  100
min_perf_pct  22
no_turbo      0
num_pstates   28
status        active
turbo_pct     33

$ cd /sys/devices/system/cpu/cpu0/cpufreq
$ paste <(ls *) <(cat *) | column -s $'\t' -t
affected_cpus                             0
cpuinfo_max_freq                          3500000
cpuinfo_min_freq                          800000
cpuinfo_transition_latency                4294967295
energy_performance_available_preferences  default performance balance_performance balance_power power 
energy_performance_preference             balance_performance
related_cpus                              0
scaling_available_governors               performance powersave
scaling_cur_freq                          1939478
scaling_driver                            intel_pstate
scaling_governor                          powersave
scaling_max_freq                          3500000
scaling_min_freq                          800000
scaling_setspeed                          <unsupported>

    From this answer I just posted on Stack Exchange: Get all available frequency steps copy and paste this function into your terminal:

    ApproximateFrequencies () {
    NumSteps=$(cat /sys/devices/system/cpu/intel_pstate/num_pstates)
    MinFreq=$(cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_min_freq)
    MaxFreq=$(cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_max_freq)
    LastFreq=$MinFreq
    StepRate=$((( $MaxFreq - $MinFreq ) / $NumSteps))
    for ((n=0;n<=$NumSteps;n++)); do
        echo $LastFreq
        LastFreq=$(( $LastFreq + $StepRate))
    done
}

    Then use this to display frequencies:

    $ ApproximateFrequencies | column
800000  1089284 1378568 1667852 1957136 2246420 2535704 2824988 3114272 3403556
896428  1185712 1474996 1764280 2053564 2342848 2632132 2921416 3210700 3499984
992856  1282140 1571424 1860708 2149992 2439276 2728560 3017844 3307128

    If you don't have column installed then omit | column portion of command.

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