Re: Where to go to learn about reducing electricity use?
On Tue, Jan 02, 2007 at 09:19:34AM -0600, Hugo Vanwoerkom wrote:
> Douglas Tutty wrote:
> >On Mon, Jan 01, 2007 at 07:30:40PM -0600, Reid Priedhorsky wrote:
> >>On Tue, 02 Jan 2007 01:40:11 +0100, Douglas Tutty wrote:
> >>>On Mon, Jan 01, 2007 at 05:06:02PM -0600, Reid Priedhorsky wrote:
> >>>>I would like to make my Etch box use less power, but I'm having a hard
> >>>>time consolidating all the information I'm finding. Is there a package I
> >>>>can install or a web page I can read that is a gentle guide to reducing
> >>>>power usage?
> >>>A good place to start may be something like the laptop-howto.
> >>>What power are you trying to reduce? Beware spinning down drives to
> >>>reduce power; spinning up reduces drive life.
> >>Thanks for your reply. It is a self-built Athlon desktop, though I assume
> >>much of the advice in the laptop-howto will be relevant. I will take a
> >>look. I'm happy to provide more specs on the box if that will be helpful.
> >>I'm not really sure how to answer your question. I know that spinning down
> >>drives is not such a good idea, and that I can reduce processor speed when
> >>idle (though how I don't know), but beyond that I don't have a good idea
> >>of what options are available to me.
> >Hi Reid,
> >I'm running Etch amd64 on my box (Athlon 3800+, Asus M2N-SLI Deluxe MB,
> >1 GB stick of DDR2 800, dual Seagate Barracuda 80 GB drives, DVD burner,
> >Asus nVidia 7300 GT silent GPU, in a CoolerMaster Stacker case with
> >cross-flow fan, blow-hole fan, three drive modules with 120 mm fans, CM
> >iGreen 600W PSU).
> >I have the MB handle the fan speeds (adjusts for temperature, not for
> >quiet) and most of the time can't hear anything but a slight directional
> >high-pitch from the CPU fan.
> >I just put an ampmeter on it during boot and it uses 1.2 A at 120 V so
> >that's 100W.
> >I note that theres a package to throttle the CPU based on load. I don't
> >know if this reduces the power consumption for what you're looking for.
> >It may primarily just reduce the CPU temperature (although mine hovers
> >at around 40 C).
> >Why are you worried about power consumption on a desktop?
> I measure exactly my system uptime/month and the KWH used where the
> computer and a desklamp are the only devices using electricity.
> The latest data shows:
> Mon May 01-05:38:44 04595 == 89 KWH 1 month 303:50 == 205 mins/KWH + Fan
> Thu Jun 01-05:52:17 04687 == 92 KWH 1 month 284:30 == 186 mins/KWH + Fan
> Sat Jul 01-09:05:37 04769 == 82 KWH 1 month 232:35 == 170 mins/KWH + Fan
> Tue Aug 01-09:43:58 04851 == 82 KWH 1 month 271:15 == 198 mins/KWH + Fan
> Fri Sep 01-09:27:08 04932 == 81 KWH 1 month ---not running
> Sun Oct 01-09:31:20 05001 == 69 KWH 1 month 238:55 == 208 mins/KWH
> Wed Nov 01-07:06:51 05069 == 68 KWH 1 month 236:20 == 208 mins/KWH
> Fri Dec 01-07:50:31 05127 == 58 KWH 1 month 228:55 == 236 mins/KWH - no Fan
> Mon Jan 01-06:37:15 05211 == 84 KWH 1 month 222:35 == 159 mins/KWH ???
> no Fan ????
> So I get variations between 159 - 236 mins/KWH, which is a huge variation.
> E.g. this month the system uptime was almost the same as last month ( -
> 6 hours) yet the difference in KWH was a whopping 26 KWH!
> And the explanation? Can that be accounted for by what the system was
> running? E.g. a new USB disk?
> (geographical location = Mexico)
I think I have the math right: 60000 Watt-Minutes = 1 KWH; 60000 / 159 =
377 Watts. 60000 / 236 = 254 = 254 Watt.
How big is your desk lamp?
The other issue is power-factor. Hydro meters measure KWH (watt-time,
in effect energy in jouls) whereas power supplies use Volt-Amp.
The last time I looked at this seriously was when I was living in the
bush (in Canada) with unreliable power and had the whole house on an
inverter/battery setup. The pure sine-wave inverter did the
power-factor correction and my P-75 used 20 W with one hard drive.