Date: Thu, 17 Jan 2008 11:15:35 +1030 From: "Daniel O'Connor" <doconnor@gsoft.com.au> To: freebsd-current@freebsd.org Cc: njl@freebsd.org, bruno@freebsd.org, Stefan Lambrev <stefan.lambrev@moneybookers.com>, Igor Mozolevsky <igor@hybrid-lab.co.uk>, Dag-Erling =?utf-8?q?Sm=C3=B8rgrav?= <des@des.no>, Maxim Sobolev <sobomax@digifonica.com> Subject: Re: powerd adaptive mode latching Message-ID: <200801171115.43663.doconnor@gsoft.com.au> In-Reply-To: <478930D2.90806@digifonica.com> References: <a2b6592c0801110351l382959ffh1d55f2bcd2e6ca1b@mail.gmail.com> <a2b6592c0801111119r148d3697hf75a59b7bf74d540@mail.gmail.com> <478930D2.90806@digifonica.com>
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[-- Attachment #1 --] On Sun, 13 Jan 2008, Maxim Sobolev wrote: > I wonder if somebody did measurement of power consumption with powerd > and without it on typical tasks. There is very interesting idea in > the last issue of ACM Queue that it might be much more beneficial to > run CPU at the full speed and then switch it to low-power mode as > soon as possible in the idle loop than to run longer at reduced speed > for a longer period of time. I did a bit of testing on a road trip once using acipconf -i 0 to measure current draw. One problem with it is that it lags behind actual usage by a few seconds (presumably averaging it). Still, at full steam (md5'ing /dev/zero at 1.4GHz) my laptop uses ~34W vs ~20W idle (which is ~300MHz depending on what KDE is doing :). Turning the LCD off saves about 4W too. I set my powerd flags like so.. powerd_enable="YES" powerd_flags="-i 70 -r 30 -a adaptive -b adaptive -n adaptive -p 200" -- Daniel O'Connor software and network engineer for Genesis Software - http://www.gsoft.com.au "The nice thing about standards is that there are so many of them to choose from." -- Andrew Tanenbaum GPG Fingerprint - 5596 B766 97C0 0E94 4347 295E E593 DC20 7B3F CE8C [-- Attachment #2 --] -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.4 (FreeBSD) iD8DBQBHjqU35ZPcIHs/zowRAvmQAJ40Fg6/SK/oXz3e23BHL8olhU8PtQCeLmd1 s1IrNUGT79YyNxZX1DH2ArQ= =dPzA -----END PGP SIGNATURE-----
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