Date: Thu, 12 Jan 2006 13:25:57 +1030 From: "Daniel O'Connor" <doconnor@gsoft.com.au> To: freebsd-stable@freebsd.org Cc: Mike Jakubik <mikej@rogers.com>, stable@freebsd.org Subject: Re: powerd effectiveness Message-ID: <200601121326.18384.doconnor@gsoft.com.au> In-Reply-To: <43C5A261.1020407@rogers.com> References: <43C5A261.1020407@rogers.com>
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--nextPart1367710.h4BoA2S3SE Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Content-Disposition: inline On Thu, 12 Jan 2006 10:57, Mike Jakubik wrote: > It seems that powerd does very little in terms of reducing heat, and > sacrifices performance while doing so. Am i wrong to assume that > lowering the cpu's frequency should reduce consumed power, and therefore > reduce the amount of heat produced? I have tested with mbmon and i see > no difference between an idle system running with powerd at 75mhz, and > at full rate without. Also, while testing the speed of a php script, i If you want to test how much heat your system draws for a given clock speed= =20 you should dispense with powerd and just set the frequency by hand, ie.. sysctl dev.cpu.0.freq=3DXXX powerd won't run your CPU at a specific clock frequency - it varies the CPU= =20 frequency based on current load conditions. Do you have thermally controlled fans? If so I wouldn't expect the temperat= ure=20 to vary with clock speed very much at all. > found myself refreshing it quickly in the browser to see the results of > the timers. I was getting sporadic results, on an otherwise idle system. > I noticed that if anything cpu intensive ran in the background, my > script would execute quicker. I disabled powerd and restored the > frequency, at this point i got more consistent results, and the script > would execute over 100msec faster. It seems like its not adjusting the The powerd defaults do not change frequency that quickly - every 500ms by=20 default. I run it with '-p 200' and it seems fine although you do notice it= =20 'stick' sometimes (where the CPU change doesn't happen quickly enough). You could try what I do but there are some systems which are very slow to=20 change clock speed so this could be an impediment. > clock fast enough. Are these problems with powerd or just my hardware? > It is an old athlon system, running on the via133 chipset . I'm suprised a system this old even supports a clock speed as low as 75Mhz. =2D-=20 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 --nextPart1367710.h4BoA2S3SE Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.2 (FreeBSD) iD8DBQBDxcVS5ZPcIHs/zowRAl+jAKCYATIA/T2oLfSVWs8cPDT5arHTyACeLIkm GHDG2DLfP5ja2VHF3nHlS0k= =rsk4 -----END PGP SIGNATURE----- --nextPart1367710.h4BoA2S3SE--
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