I just switched from Windows 10 to Ubuntu 16.04 LTS and I am quite satisfied with it after installing and configuring Gnome Shell. However, like everyone, I encounter a significant drop in terms of battery life compared to Windows 10 (5 hours to 1.5h).
I first tried to enable Optimus by installing Bumblebee but did not succeed (XORG error). As I don't really need high 3D performance, I decided to stick with the "low" performance Intel HD Graphic with the command
sudo prime-select intel && sudo reboot
After restart, I powertop for 5 minutes and surprisingly got a 20W discharge rate which is freaking high. On the other hand, if I switch to the Nvidia card, I get 14W discharge rate with powertop, which confuses me a lot. On the Nvidia card, I get 3h battery life but still far from Windows. How come the battery life on Intel HD Graphic is worse than on Nvidia Graphic card?
I have a CPU i7 4710HQ with a Nvidia Geforce GTX860M.
PS : TLP does not improve my battery life a bit, but LMT gives lightly better battery life.