Processor
CPU_SCALING_GOVERNOR_ON_AC/BAT
CPU_SCALING_GOVERNOR_ON_AC=powersave
CPU_SCALING_GOVERNOR_ON_BAT=powersave
Selects the CPU scaling governor for automatic frequency scaling. Configuration depends on the active scaling driver:
intel_pstate
For Intel Core i 2nd gen. (“Sandy Bridge”) or newer Intel CPUs. Supported governors are:
performance
powersave – default
intel_cpufreq
Starting with kernel 5.7, the intel_pstate scaling driver selects “passive mode” aka intel_cpufreq for CPUs that do not support hardware-managed P-states (HWP), i.e. Intel Core i 5th gen. or older.
Supported governors are identical to the acpi-cpufreq driver below, the default scheduler is schedutil.
acpi-cpufreq
For AMD, older Intel CPUs and other vendors. Supported governors are:
conservative
ondemand – default for most distributions
userspace
powersave
performance
schedutil – default for newer kernels and the intel_cpufreq driver above
Note
Refer to the output of tlp-stat -p to determine the active scaling driver and available governors.
Important
Default governors listed above are power efficient for almost all workloads, therefore kernel devs and most distributions have chosen them as such. So before changing the scaling governor please do your research about the advantages and disadvantages of the others (refer to the links on the bottom of this page).
CPU_SCALING_MIN/MAX_FREQ_ON_AC/BAT
CPU_SCALING_MIN_FREQ_ON_AC=0
CPU_SCALING_MAX_FREQ_ON_AC=9999999
CPU_SCALING_MIN_FREQ_ON_BAT=0
CPU_SCALING_MAX_FREQ_ON_BAT=9999999
Set the min/max frequency available for the scaling governor. Possible values depend on your CPU. For available frequencies consult the output of tlp-stat -p.
Hints:
Do not use this setting with the intel_pstate scaling driver, use CPU_MIN/MAX_PERF_ON_AC/BAT instead
Min/max frequencies must always be specified for both modes i.e. AC and BAT
To enable processor defaults comment all four settings and reboot
Lowering the max frequency on battery power may not conserve power; best results are to be expected from the ondemand governor without frequency limits
CPU_ENERGY_PERF_POLICY_ON_AC/BAT
Version 1.3 and higher
CPU_ENERGY_PERF_POLICY_ON_AC=balance_performance
CPU_ENERGY_PERF_POLICY_ON_BAT=balance_power
Set Intel CPU energy/performance policies HWP.EPP and EPB (in order of increasing power saving):
performance
balance_performance
default
balance_power
power
Default when unconfigured: balance_performance (AC), balance_power (BAT)
Hints:
HWP.EPP (hardware-managed P-states): requires kernel 4.10, intel_pstate scaling driver and Intel Core i 6th gen. (“Skylake”) or newer CPU
EPB: requires kernel 5.2 (or module msr and x86_energy_perf_policy from linux-tools), intel_pstate or intel_cpufreq scaling driver and Intel Core i 2nd gen. (“Sandy Bridge”) or newer CPU
HWP.EPP and EPB are mutually exclusive: when EPP is available, Intel CPUs will not honor EPB. Only the matching feature will be applied by TLP and shown by by tlp-stat -p.
CPU_HWP_ON_AC/BAT
Version 1.2.2 and lower
CPU_HWP_ON_AC=balance_performance
CPU_HWP_ON_BAT=balance_power
Set Intel CPU energy/performance policy HWP.EPP. Possible values are (in order of increasing power saving):
performance
balance_performance
default
balance_power
power
Hints:
Requires kernel 4.10, intel_pstate scaling driver and Intel Core i 6th gen. (“Skylake”) or newer CPU
For version 1.3 and higher use CPU_ENERGY_PERF_POLICY_ON_AC/BAT instead
CPU_MIN/MAX_PERF_ON_AC/BAT
CPU_MIN_PERF_ON_AC=0
CPU_MAX_PERF_ON_AC=100
CPU_MIN_PERF_ON_BAT=0
CPU_MAX_PERF_ON_BAT=30
Define the min/max P-state for Intel CPUs. Values are stated as a percentage (0..100%) of the total available processor performance.
Hints:
Requires intel_pstate or intel_cpufreq scaling driver and Intel Core i 2nd gen. (“Sandy Bridge”) or newer CPU
The driver imposes a limit > 0 on the min P-state, see min_perf_pct in the output of tlp-stat -p
This setting is intended to limit the power dissipation of the CPU
CPU_BOOST_ON_AC/BAT
CPU_BOOST_ON_AC=1
CPU_BOOST_ON_BAT=0
Configure CPU “turbo boost” (Intel) or “turbo core” (AMD) feature (0 = disable / 1 = allow).
Note
A value of 1 does not activate boosting, it just allows it.
CPU_HWP_DYN_BOOST_ON_AC/BAT
Version 1.4 and higher
CPU_HWP_DYN_BOOST_ON_AC=1
CPU_HWP_DYN_BOOST_ON_BAT=0
Configure the Intel CPU HWP dynamic boost feature:
0 - disable
1 - enable
Hint: requires intel_pstate scaling driver in active mode and Intel Core i 6th gen. (“Skylake”) or newer CPU
SCHED_POWERSAVE_ON_AC/BAT
SCHED_POWERSAVE_ON_AC=0
SCHED_POWERSAVE_ON_BAT=1
Minimize number of used CPU cores/hyper-threads under light load conditions (1 = enabled, 0 = disabled). Depends on kernel and processor model.
Default when unconfigured: 0 (AC), 1 (BAT)
ENERGY_PERF_POLICY_ON_AC/BAT
Version 1.2.2 and lower
ENERGY_PERF_POLICY_ON_AC=performance
ENERGY_PERF_POLICY_ON_BAT=power
Set Intel CPU energy/performance policy EPB. Possible values are (in order of increasing power saving):
performance
balance-performance
default (deprecated: normal)
balance-power
power (deprecated: powersave)
Hints:
Requires intel_pstate or intel_cpufreq scaling driver and Intel Core i 2nd gen. (“Sandy Bridge”) or newer CPU
Requires the kernel module msr and the tool x86_energy_perf_policy matching your kernel version
For version 1.3 and higher use CPU_ENERGY_PERF_POLICY_ON_AC/BAT instead
See also
CPU Performance Scaling – kernel documentation covering scaling governors et al.
intel_pstate CPU Performance Scaling Driver – driver documentation
Intel Hardware P-State (HWP) / Intel Speed Shift – a consideration of HWP.EPP
Intel Performance and Energy Bias Hint – EPB documentation
Improvements in CPU frequency management – LWN article covering the schedutil governor