Re: Does Linux 4.16.1 blast out battery time? (9h+ -> 3h+)

[Tomáš Čech]

On Fri, Apr 13, 2018 at 11:36:03AM +0530, Pierre Neidhardt wrote:
> I just ran a `guix system reconfigure` yesterday and Guix pulled Linux
> 4.16.1.  Upon reboot, my laptop's battery time had changed from 9h+ to
> 3h+!  Quite a dramatic regression indeed...
>
> General usage (startup time, etc.) seems to be somewhat slower as well.
>
> As a test, I ran another system reconfigure, changing only the kernel
> version: now on 4.14.33, I'm back to 9h+.
>
> Does anyone know something about this or should I reach out for the
> Linux mailing list?
>
> Note that before installing GuixSD, I was running Void Linux with kernel
> ~4.14.5 (off the top of my head) and battery time was 12h+.  This might
> be due to the discrete Nvidia card which was completely shut off by
> default, while it's now running with nouveau on GuixSD but I don't know
> how to turn it off.
>
> Insights?

I'm not aware of any regression but I'd recommend to install powertop
and check, which processes are preventing CPU from switching to power
saving modes.

Sometimes it provides interesting results - I usually can spend like
40% more time on battery by closing Icecat and Pavucontrol.

It also can help you with tuning common power management controls.

Best regards,

S_W

signature.asc
Description: Digital signature