Get powertop2 from AUR to verify that this script is working properly (check the Tunables before and after you run the script). They should all turn to "good". One other thing to note is that the script runs when the power state is toggled. Thus, if you are plugged in, the script restores things to the non-tuned state. So, to verify that the script is working, you should start powertop2 with your computer plugged in and then unplug it. It takes a few seconds for powertop2 to refresh the Tunables section.

This was written for my thinkpad T420, but it should work on nearly all current-gen thinkpads with the intel HD3000 card.

powersave.sh script is here: https://gist.github.com/92980c0a67e0b2d1bd43

powertop2 is here: https://aur.archlinux.org/packages.php?ID=48935

proof of the results is here (forgive the bad font fringing, i got the power going before making the fonts look good): http://i.imgur.com/rN09E.png

You should also edit your /boot/grub/menu.lst file to pass the special powersaving kernel flags at boot. The relevant stanza in mine looks like this:

  # (0) Arch Linux
  title  Arch Linux
  root   (hd0,0)
  kernel /vmlinuz-linux root=/dev/sda3 ro pcie_aspm=force i915.i915_enable_rc6=1
  initrd /initramfs-linux.img

  #grub-install --no-floppy /dev/sda

I'm running the nVidia chip exclusively, but when I get around to it, I'll probably switch, as I'm running an openbox desktop that just doesn't need that kind of graphics acceleration. I have yet to figure out a painless way of switching between the two, but that's probably because I haven't really worked on it much.

I have only ATI cards and the difference between open source driver and proprietary driver is world apart. With radeon I have +2 hours, with fglrx it's ~4 hours.