Date: Fri, 14 Dec 2007 22:28:33 +1100 (EST) From: Ian Smith <smithi@nimnet.asn.au> To: =?ISO-8859-9?Q?cihan_k=F6me=E7o=F0lu?= <cihankomecoglu@gmail.com> Cc: freebsd-acpi@freebsd.org Subject: Re: energy mesaurement Message-ID: <Pine.BSF.3.96.1071214211620.13773A-100000@gaia.nimnet.asn.au> In-Reply-To: <9874aea0712140014u4c1891dejf550db82bbc0a18e@mail.gmail.com>
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On Fri, 14 Dec 2007, [ISO-8859-9] cihan kömeçoğlu wrote: > I need to mesaure laptop's energy. > How can I do? I searched any program but I can't find. The best way is to borrow an inline or clamp wattmeter to actually measure real power usage of your laptop + adaptor/charger in use. 'acpiconf -i0' (assuming battery #0) should tell you quite a bit about present entire power usage in milliWatts, while running on battery. You may need to take several readings with one load, there's some time lag. I think 'Present rate' while charging refers to battery charging rate rather than usage, or perhaps it includes usage too. Assuming your laptop runs ACPI and has cpu frequency control, you can run 'powerd -v' in foreground mode in a console for a given interval, say 10 minutes, and when you exit powerd by ^C you'l be told how many Joules have been used (by the CPU anyway). I don't know the conversion factor between Joules and Watt-hours. CPU usage may or may not indicate something like half of the total power consumed by the laptop - it does on my T23 when running at full speed anyway, but it's not really modern. 'sysctl dev.cpu.0.freq_levels' shows CPU power usage at each of the various speeds, in milliWatts. Failing that, you'll have to rely on manufacturer's specs, or methods like dividing the battery's rated capacity by how long it will run the machine, but that depends on battery condition (see acpiconf -i0 again) HTH, Ian
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