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Date:      Tue, 5 May 2009 01:00:00 +0400
From:      Dmitry Kolosov <ivakras1@gmail.com>
To:        freebsd-acpi@freebsd.org
Subject:   Re: Fighting for the power.
Message-ID:  <200905050100.00739.ivakras1@gmail.com>
In-Reply-To: <49FE64C5.2020507@FreeBSD.org>
References:  <49FE1826.4060000@FreeBSD.org> <20090504011421.GI6901@egr.msu.edu> <49FE64C5.2020507@FreeBSD.org>

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On =F0=CF=CE=C5=C4=C5=CC=D8=CE=C9=CB 04 =CD=C1=D1 2009 07:45:09 Alexander M=
otin wrote:
> Adam McDougall wrote:
> > On Mon, May 04, 2009 at 01:18:14AM +0300, Alexander Motin wrote:
> >=20
> >   I would like to summarize some of my knowledge on reducing FreeBSD po=
wer
> >   consumption and describe some new things I have recently implemented =
in
> >   8-CURRENT. The main character of this story is my 12" Acer TravelMate
> >   6292 laptop with C2D T7700 2.4GHz CPU, 965GM chipset and SATA HDD, un=
der
> >   amd64 8-CURRENT.
> >  =20
> > Great list!  May I suggest screen brightness and DPMS as another tool
> > to save power, I've measured a 5W difference from the screen draw.
> > Keeping the brightness as low as tolerable helps considerably, but=20
> > also using 'xset dpms 120 120 120' (modify to taste) in .xinitrc to
> > turn off the screen after 2 minutes helps when the laptop isn't being
> > used every second.  May need this in xorg.conf:
> > Option             "dpms"
>=20
> Yes, backlight is also important. But there is not so much things could=20
> be done.
>=20
> When I am leaving system for some time, I can just close the lid, if not=
=20
> put system into S3 state, which require very small power (at least I was=
=20
> unable to really measure it without all-day-long testing). Thanks to=20
> jkim@ we have more or less working S3 state for amd64 now.
>=20
I'm using sysctl to controll brightness of my lcd (wrongly marked as crt by=
 sysctl, but it works fine):
hw.acpi.video.crt1.brightness: 95 - current brightness of lcd (crt)
hw.acpi.video.crt1.fullpower: 95 - top level of brightness set by acpi_vide=
o if AC plugged
hw.acpi.video.crt1.economy: 43 - bottom level of brightness set by acpi_vid=
eo if AC unplugged
hw.acpi.video.crt1.levels: 95 43 20 24 28 32 37 43 50 59 69 81 95 - various=
 brightness levels can be set manual by sysctl

It works fine for me, and it's easy to write a script to react on different=
 events during a day.



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