[Powertop] Powertop usage

Hi, I have trouble understanding the output of powertop on my macbook air: Power est. Usage Events/s Category Description 5.34 W 100.0% Device USB device: Apple Internal Keyboard / Trackpad (Apple Inc.) 889 mW 15.8 ms/s 168.2 Process /usr/bin/X :0 -auth /var/run/lightdm/root/:0 -nolisten tcp vt7 -novtswitch 729 mW 2.9 pkts/s Device Network interface: eth0 (wl) despite tweaking everything possible about the Apple keyboard. My global consumption is 8 Watts, so I find really strange 2/3 of it is in the keyboard. Is, for some reason, powertop attributing to the apple keyboard the consumption overhead of the computer? Thanks in advance for answers, and thanks to the powertop developers for their tool, Pascal