|Out of the box.||43 watts|
|Editing /etc/default/grub (see below)||36 watts|
|Disabling the useless ATI card||13 watts !!|
Power usage was taken from cat /proc/acpi/battery/BAT0/statewith the CPU practicly idle (less than 2%).
Edit /etc/default/grub to the following:
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash pcie_aspm=force i915.i915_enable_rc6=1 i915.i915_enable_fbc=1 i915.lvds_downclock=1 acpi_backlight=vendor acpi_osi=Linux"
from this article on Phoronix. (I have added the last two acpi functions to enable backlight control) and run update-grub.
To disable the ATI card edit /etc/rc.local and add the following line at the top: sudo echo OFF > /sys/kernel/debug/vgaswitcheroo/switch.
This makes the laptop usable for all except gaming, although the integrated Intel graphics is surprisingly powerful for what it is!
I will update when (if) I figure out the ATI graphics.
OK, so I didn't figure out the ATI graphics, but ATI did! You can find more information on setting up the ATI card here.