Use cpufrequtils to Adjust Processor Settings

From odroid US
Revision as of 11:24, 25 June 2013 by Osterluk (Talk | contribs)

(diff) ← Older revision | Latest revision (diff) | Newer revision → (diff)
Jump to: navigation, search

Note: This does not work on odroids with 3.8.x kernel, per Link to HK forum topic

This tutorial is for odroid users running Debian-based distros, including Ubuntu.

The Samsung Exynos 4412 SoC is intended for mobile devices, such as tablets and smartphones. To save power and heat. It shuts down CPUs as needed and throttles back their speed to save battery life. You can elect to change how your board works -- without rebuilding the kernel.

Get a terminal session as root. Then install cpufrequtils:

apt-get install cpufrequtils

Here is a nice writeup on usage notes: http://www.thinkwiki.org/wiki/How_to_use_cpufrequtils

Use the cpufreq-info command to get information:

cpufrequtils 008: cpufreq-info (C) Dominik Brodowski 2004-2009
Report errors and bugs to cpufreq@vger.kernel.org, please.
analyzing CPU 0:
  driver: exynos_cpufreq
  CPUs which run at the same hardware frequency: 0
  CPUs which need to have their frequency coordinated by software: 0
  maximum transition latency: 11.0 us.
  hardware limits: 200 MHz - 2.00 GHz
  available frequency steps: 2.00 GHz, 1.92 GHz, 1.80 GHz, 1.70 GHz, 1.60 GHz, 1.50 GHz, 1.40 GHz, 1.30 GHz, 1.20 GHz, 1.10 GHz, 1000 MHz, 900 MHz, 80z
  available cpufreq governors: userspace, powersave, conservative, ondemand, performance
  current policy: frequency should be within 200 MHz and 1.60 GHz.
                  The governor "ondemand" may decide which speed to use
                  within this range.
  current CPU frequency is 200 MHz (asserted by call to hardware).
  cpufreq stats: 2.00 GHz:0.00%, 1.92 GHz:0.00%, 1.80 GHz:0.00%, 1.70 GHz:0.00%, 1.60 GHz:99.54%, 1.50 GHz:0.00%, 1.40 GHz:0.00%, 1.30 GHz:0.00%, 1.20)


You can turn on the performance governor like this:

cpufreq-set -g performance

Overclocking

Default max clock was set to 1.7Ghz in the latest release. The max frequency can be adjusted to one of the following: [ 2000000 | 1920000 | 1800000 | 1704000 ]. 1704000 is the default.

Set the value like this: (for example 1.9GHz)

echo 1920000 > /sys/devices/system/cpu/cpu0/cpufreq/scaling_max_freq

You may need a cooling fan for this overclocking.