Comment passer d'une autonomie de 2h à presque 5h :

On ajoute quelques paramêtres à passer au kernel en remplacant la ligne GRUB_CMDLINE_LINUX_DEFAULT :

sudo nano /etc/default/grub
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash i915.i915_enable_fbc=1 i915.i915_enable_rc6=1 pcie_aspm=force" 
update-grub

Pour désactiver la carte Radeon, on va utiliser vgaswitcheroo (pas besoin d'installer quoi que ce soit)

sudo nano /etc/rc.local
# Ajouter cette ligne avant le exit 0 :
echo OFF > /sys/kernel/debug/vgaswitcheroo/switch
sudo nano /etc/pm/sleep.d/10_disable_radeon
#!/bin/sh
# Action script ensures that discrete graphics card is disabled after
# resuming from standby/hibernate
#
#
case "${1}" in
resume|thaw)
echo OFF > /sys/kernel/debug/vgaswitcheroo/switch
;;
esac
sudo chmod +x /etc/pm/sleep.d/10_disable_radeon

On s'occupe maintenant du mode économie d'énergie :

sudo apt-get install ethtool
sudo nano /etc/pm/power.d/powersavings
#!/bin/sh
# Shell script to reduce energy consumption when running battery. Place
# it in /etc/pm/power.d/ and give execution rights.
# This is a modified version of an original script of by Skumpic,
# available here: http://blog.liberailvoip.it/2010/04/27/
# ubuntu-lucid-lynx-acer-aspire-one-impostazioni-ottimizzate-
# autonomia-prestazioni/
# Disable Wake On Lan
ethtool -s eth0 wol d
if on_ac_power; then
# ----- Start AC powered settings #
# Disable laptop mode
echo 0 > /proc/sys/vm/laptop_mode
# Set SATA channel: max performance
for foo in /sys/class/scsi_host/host*/link_power_management_policy;
do echo max_performance > $foo;
done
# Set Max Power for wifi interface
# change value according to your hardware!
iwconfig wlan0 txpower 14   
# Disable wifi power saving
iwconfig wlan0 power off
# CPU Governor: Performance
for foo in /sys/devices/system/cpu/cpu*/cpufreq/scaling_governor;
do echo performance > $foo;
done
# Disabile USB autosuspend
for foo in /sys/bus/usb/devices/*/power/control;
do echo on > $foo;
done
# Disable PCI autosuspend
for foo in /sys/bus/pci/devices/*/power/control;
do echo on > $foo;
done
# Disabile audio_card power saving
echo 0 > /sys/module/snd_hda_intel/parameters/power_save_controller
echo 0 > /sys/module/snd_hda_intel/parameters/power_save
# Set maximum display backlight
echo 15 > /sys/class/backlight/acpi_video0/brightness
# ----- End AC powered settings #
else
# ----- Start battery powered settings #
# Enable Laptop-Mode disk writing
echo 5 > /proc/sys/vm/laptop_mode
# Set SATA channel to power saving
for foo in /sys/class/scsi_host/host*/link_power_management_policy;
do echo min_power > $foo;
done
# Activate wifi power saving
iwconfig wlan0 power timeout 500ms
# Reduce wifi txpower
iwconfig wlan0 txpower 5
# Select Ondemand CPU Governor
for foo in /sys/devices/system/cpu/cpu*/cpufreq/scaling_governor;
do echo ondemand > $foo;
done
# Activate USB autosuspend
echo auto > /sys/bus/usb/devices/1-1.1/power/control # Fingerprint sensor
echo auto > /sys/bus/usb/devices/1-1.3/power/control # Webcam
# Activate PCI autosuspend
for foo in /sys/bus/pci/devices/*/power/control;
do echo auto > $foo;
done
# Activate audio card power saving
# (sounds shorter than 5 seconds will not be played)
echo 5 > /sys/module/snd_hda_intel/parameters/power_save
echo 1 > /sys/module/snd_hda_intel/parameters/power_save_controller
# Set medium display backlight
echo 5 > /sys/class/backlight/acpi_video0/brightness
# ----- End battery powered settings #
fi

Redémarrez. Je viens de passer de 25 minutes restantes à 1h49 - not bad. J'ai le temps de finir mon café avant de rebrancher :)

Source : http://blog.ejbca.org/2012/02/ubuntu-gnulinux-1204-precise-on-sony.html