CPUPOWER-SET(1) cpupower Manual CPUPOWER-SET(1)NAMEcpupower-set - Set processor power related kernel or hardware configu‐
cpupower set [ -b VAL ] [ -s VAL ] [ -m VAL ]
cpupower set sets kernel configurations or directly accesses hardware
registers affecting processor power saving policies.
Some options are platform wide, some affect single cores. By default
values are applied on all cores. How to modify single core configura‐
tions is described in the cpupower(1) manpage in the --cpu option sec‐
tion. Whether an option affects the whole system or can be applied to
individual cores is described in the Options sections.
Use cpupower info to read out current settings and whether they are
supported on the system at all.
Sets a register on supported Intel processore which allows software
to convey its policy for the relative importance of performance
versus energy savings to the processor.
The range of valid numbers is 0-15, where 0 is maximum performance
and 15 is maximum energy efficiency.
The processor uses this information in model-specific ways when it
must select trade-offs between performance and energy efficiency.
This policy hint does not supersede Processor Performance states
(P-states) or CPU Idle power states (C-states), but allows software
to have influence where it would otherwise be unable to express a
For example, this setting may tell the hardware how aggressively or
conservatively to control frequency in the "turbo range" above the
explicitly OS-controlled P-state frequency range. It may also tell
the hardware how aggressively it should enter the OS requested C-
This option can be applied to individual cores only via the --cpu
Setting the performance bias value on one CPU can modify the set‐
ting on related CPUs as well (for example all CPUs on one socket),
because of hardware restrictions. Use cpupower -c all info -b to
This options needs the msr kernel driver (CONFIG_X86_MSR) loaded.
--sched-mc, -m [ VAL ]
--sched-smt, -s [ VAL ]
--sched-mc utilizes cores in one processor package/socket first
before processes are scheduled to other processor packages/sockets.
--sched-smt utilizes thread siblings of one processor core first
before processes are scheduled to other cores.
The impact on power consumption and performance (positiv or nega‐
tiv) heavily depends on processor support for deep sleep states,
frequency scaling and frequency boost modes and their dependencies
between other thread siblings and processor cores.
Taken over from kernel documentation:
Adjust the kernel's multi-core scheduler support.
Possible values are:
0 - No power saving load balance (default value)
1 - Fill one thread/core/package first for long running threads
2 - Also bias task wakeups to semi-idle cpu package for power
SEE ALSOcpupower-info(1), cpupower-monitor(1), powertop(1)AUTHORS--perf-bias parts written by Len Brown <email@example.com>
Thomas Renninger <firstname.lastname@example.org>