Why does my computer get less battery life with Ubuntu compared to Windows?
Last year I purchased a Dell Inspiron 5315 laptop shipping with Windows 7 preinstalled. I installed Ubuntu 10.10 alongside it with dual-booting. On upgrading to Ubuntu 11.10, I was upset to find I now get less than one hour of battery life! Windows 7 gives me 2.5 hours of running time.
Is there any possible explanation why my battery is running out faster with Ubuntu? Can anybody tell me better power options?
Solution 1:
It's claimed that Windows 7 provides better battery life than Ubuntu, I haven't compared it on my laptops though. That said there are many approaches to increase it. Here are those I've found the most effective:
- Install package laptop-mode-tools. It switches your laptop to a "laptop mode" whenever it's on the battery, hard disks are spun down, power saving mode is turned on for peripherals/devices etc.
- Use task manager to find the most intensive processes and disable them (check PowerTOP as well). Also disable boot services you don't need (
apt-get install bum) and services started by your graphical window manager. - Check that your CPU frequency is scaled down dynamically (
cat /proc/cpuinfo). - Reduce screen brightness (display consumes the most power).
- Some random tips might help, i.e. see this answer.
Solution 2:
There is a reasonably well known kernel issue with power management on PCI Express systems.
Try editing your boot-up grub entry to include pcie_aspm=force to the kernel parameters, and seeing if that improves your power consumption.