Yes, that sounds exactly as it should work, I have slightly better performance – something like 2.5 hours on Nvidia. That’s the whole reason for the Optimus technology – it is supposed to allow you to choose whether you want great battery life of 3D performance, by having the Intel integrated graphics handle all the standard work, which is very energy efficient, and when you want 3D performance you start the Nvidia discrete graphics and should connect the laptop to power immediately.

The purpose of the Bumblbee project that I discuss in this post is to enable this technology in Linux. When you have something running under ‘optirun’, it will enable the Nvidia graphics and will eat all the juice in the battery, and when optirun is closed, it will disable the Nvidia graphics card and stop the drain on the battery.

Its important to note (which I failed to mention in the post) that you should disable “auto detection” of Optimus compatibility in the BIOS, otherwise the BIOS will always enable the Nvidia graphics card when running under Linux and you will not get any battery saving when using just the integrated graphics.