Skylake's Linux power management is dreadful you shouldn't buy until it's fixed

Re:Skylake's Linux power management is dreadful you shouldn'... by bb85 on Wednesday April 13, 2016 @09:30PM (#11493715)

Anecdotal, but I've been running Ubuntu 15.10 for a few months on a Dell XPS 15 (9550), and with kernel 4.4 everything works flawlessly.

When idling, power consumption is 8W, and powertop shows 30% C8 and 70% C10.

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Re:Skylake's Linux power management is dreadful you shouldn'... by ggreer on Wednesday April 13, 2016 @11:25PM (#11494097)

Hmm... 8 watts sounds extremely high to me. My Broadwell laptop uses less than 3 watts when idle, and most of that is the display. Even my old Ivy Bridge MacBook Air from 2012 idles at 5W. Is there some peripheral responsible for the higher idle on your system? Maybe a hard disk or dedicated GPU? I'm curious about what's causing the difference.

CPU/GPU power usage: (≈1W) http://geoff.greer.fm/photos/screenshots/Screen%20Shot%20201...

Total power usage: (2.9W) http://geoff.greer.fm/photos/screenshots/Screen%20Shot%20201...

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Re:Skylake's Linux power management is dreadful you shouldn'... by bb85 on Thursday April 14, 2016 @08:48PM (#11501358)

You were right! I barely use it on battery so I never investigated.

I installed tlp and system went down to 5.5W idle with normal programs open. On fresh boot as low as 4.9W.

Turning the screen off shaves 2.5W, and disabling the wireless card saves ~1W.

I suspect the SSD + HDD are making part of the difference.

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