SOLVED! I tested 3.1.0rc9 and the problem was still there, than I downgraded to 2.6.39 and the problem was solved.. I was back to Natty's drain.
Now a user in ubuntuforums suggested an even better solution, that allow to use a 3.x kernel on newer sandybridge laptops and have good drain. I just have to pass the option i915.i915_enable_rc6=1 at boot. Here is the link http://ubuntuforums.org/showpost.php?p=11346775&postcount=7 Now I'm happy with it! When I just browse the web, via wi-fi, with a medium lavel display backlight it drains ~9W most of the time, with just some occasional peaks to 11-12W. Anyway, also the custum tweaks that I put in /etc/pm/power.d/ are very useful.. thay allow me to save a couple of watt at least (See comment #2 on this bug report for link). And I'm not doing anything exotic! The main things are changing the cpu governor to ondemand, and activating the automatic power management for usb and pci devices! I think ubuntu developers should consider including something similar by default! -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/863944 Title: Ubuntu 11.10 Beta 2. Increase in energy consumption To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/863944/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs