CPU Frequency Governor Linux

After reading and configureing scaling in linux and reading about how scaling and really mess with applications I disabled it on systems that I can. I wanted the systems fast anyways.

Debian and Archlinux use: cpufrequtils

Archlinux

You want cpufrequtils

cpufreq-info

I had to manually configure:

Options:

cpufreq_ondemand (default and recommended)

Dynamically switches between the CPU(s) available clock speeds based on system load

cpufreq_performance

The performance governor runs the CPU(s) at maximum clock speed

cpufreq_conservative

Similar to ondemand, but the CPU(s) clock speed switches gradually through all its available frequencies based on system load

cpufreq_powersave

Runs the CPU(s) at minimum speed

cpufreq_userspace

Manually configured clock speeds by user

Add to rc.conf:

MODULES=(... cpufreq_powersave cpufreq_userspace ...)

I have a new kernel as most archlinux users do and did not need to have the system autoload the modules because they already are.

I use this laptop like a desktop but just in case I created some aliases to switch back and forth:

alias cpu.performance='sudo cpufreq-set -r -g performance'
alias cpu.ondemand='sudo cpufreq-set -r -g ondemand'

/etc/conf.d/cpufreq 

#configuration for cpufreq control

# valid governors:
#  ondemand, performance, powersave,
#  conservative, userspace
governor="performance"

# limit frequency range (optional)
# valid suffixes: Hz, kHz (default), MHz, GHz, THz
#min_freq="2.25GHz"
#max_freq="3GHz"

# use freq to set up the exact cpu frequency using it with userspace governor
#freq=

Notes

• https://wiki.archlinux.org/index.php/CPU_Frequency_Scaling

Debian

Debian was different. It uses an old kernel but I already had cpufrequtils installed and it was configured to be up and running. It may be because on install I selected laptop utils. I do not remember.

I wanted performance and I did:

echo performance > /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor

I still had to keep the change perm across reboots so I edited /etc/sysfs.conf with:

devices/system/cpu/cpu0/cpufreq/scaling_governor = performance

Notes

• http://wiki.debian.org/HowTo/CpuFrequencyScaling
• http://idebian.wordpress.com/2008/06/22/cpu-frequency-scaling-in-linux/