I reach c8 state with hdmi connected. In fact, what I have to disconnect is ethernet because of a kernel bug.   But could you or anyone provide me some light to this issue?   Doing nothing, is 48% of the time desirable or should be ~99% if user is doing literally nothing? Is powertop still refreshing or maybe is frozen and I can't see new values?   So for me is relevant an answer which also asked @dopeytree   And please, could anyone answer me: AS