Since I bought my Laptop HP Pavilion DV6353, I couldn’t get more than 2 hours using its battery. When I upgraded to Fedora 10, My battery lasts for only an hour and half. So I decided to increase my battery life. After long time of hours reading and reading about saving power, I came up with a list of stuff that I have done and improved my battery life to almost 3 hours!!
1. eth0 driver is doing 100 interrupts per second.
after reading “modinfo forcedeth”, I had to create a file in /etc/modprobe.d/forcedeth and have the following line in it:
options forcedeth poll_interval=65534
This reduced the number of interrupts.
2. nvidia driver was consuming much of power too.. After reading its manual and searching the internet. I had to modify my /etc/X11/xorg.conf to have the following:
In the driver section:
Option “RegistryDwords” “PowerMizerEnable=0x1; PerfLevelSrc=0x2222; PowerMizerDefault=0x3; PowerMizerDefaultAC=0x2”
What I have done here is I have disabled Nvidia powermizer and I have set the clock to the lowest speed when running on battery and on mid speed when running on AC.
In the Screen section:
Option “OnDemandVBlankInterrupts” “True”
3. Kernel Tuning for laptop…
I. Enable laptop mode:
echo 5 > /proc/sys/vm/laptop_mode
II. Virtual Memory:
echo 40 > /proc/sys/vm/dirty_ratio
echo 10 > /proc/sys/vm/dirty_background_ratio
echo 1500 > /proc/sys/vm/dirty_writeback_centisecs
4. Laptop mode tools:
For Kernel tuning, I have created a script that got the default values for kernel parameters and the tuned values so that I run the script with parameters to switch between modes.