ubuntu undervoltage linux-ppc
- sudo add-apt-repository ppa:linux-phc/ppa
- sudo apt-get install build-essential linux-generic-phc linux-headers-generic-phc
- reboot
- Download PHC: http://www.linux-phc.org/forum/viewtopic.php?f=13&t=2
- tar -xvzf phc-intel-0.3.2-9.tar.gz
- cd phc-intel-0.3.2-9/
- make prepare
- make
- sudo make install
- sudo rmmod acpi_cpufreq
- sudo modprobe phc-intel
Find out default voltage setting:
- cat /sys/devices/system/cpu/cpu0/cpufreq/phc_default_vids
- Example: 35 26 19
Find out current voltage settings:
- cat /sys/devices/system/cpu/cpu0/cpufreq/phc_controls
- Example: 11:35 8:26 6:19
- This are values for 3 frequencies
- The number before the colon is the frequency id, the number after the colon is the voltage id
- The voltage can be calculated: mV = 700 + VID * 16
- 35 = 1,260V
- 26 = 1,116V
- 19 = 1,004V
Set voltage:
- As root:
- echo "11:34 8:25 6:18" > /sys/devices/system/cpu/cpu0/cpufreq/phc_controls