Disable dual graphics for better battery life on mint linux

My acer timeline x 4820TG laptop has 2 graphics cards. An onboard intel card (less powerful but battery friendly) and AMD radeon 5650 (Powerful but battery hungry). This is basically called hybrid graphics. More information can be found at https://wiki.archlinux.org/index.php/hybrid_graphics


Both the graphics cards were used to be on, and eating battery life. Also the fan would make a lot of noise.

Everything was fine when I used to run Windows 7 with the AMD drivers. Since last 2 years I have been using mint linux and it has been a cause of trouble for me since then. I finally decided to take a dig at it solve the issue.

After a couple of searches found the solution...

Use the following commands....

To list the switchable devices
-------------------------------------------------
sudo chown prabhat /sys/kernel/debug
cat /sys/kernel/debug/vgaswitcheroo/switch


To switch off discrete (Radeon) graphics card
------------------------------------------------------------

sudo chown prabhat /sys/kernel/debug/
sudo chown prabhat /sys/kernel/debug/vgaswitcheroo/switch
echo OFF > /sys/kernel/debug/vgaswitcheroo/switch


To switch on discrete graphics card
--------------------------------------------------------------

sudo chown prabhat /sys/kernel/debug/
sudo chown prabhat /sys/kernel/debug/vgaswitcheroo/switch
sudo echo ON > /sys/kernel/debug/vgaswitcheroo/switch


To switch off discrete graphics card at system startup
-----------------------------------------------------------------------------------------

sudo gedit /etc/rc.local

Add following before exit 0

chown prabhat /sys/kernel/debug/vgaswitcheroo/switch
echo OFF > /sys/kernel/debug/vgaswitcheroo/switch

*Replace prabhat with your username.

You should not need these if your kernel is >3.12 (Mine is 3.11) as the driver automatically manages the power of radeon gpu.