[6064] in Release_7.7_team
Re: Putting display to sleep on Athena
daemon@ATHENA.MIT.EDU (William Cattey)
Tue Sep 23 17:08:24 2008
In-Reply-To: <200807292038.m6TKc1r1000794@speaker-for-the-dead.mit.edu>
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Cc: Greg Hudson <ghudson@MIT.EDU>, release-team@MIT.EDU
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From: William Cattey <wdc@MIT.EDU>
Date: Tue, 23 Sep 2008 17:07:30 -0400
To: Jonathon Weiss <jweiss@MIT.EDU>
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To follow up, I looked at the Dell and HP data sheets on the 3 common
Athena video monitors for power consumption:
This year's: Dell 2009W: Max: 35w, Minimum (displaying msdos prompt):
19.4w, Active-Off: .6w
Last year's: Dell 2007WFP: Max: 75w, Typical (routine task): 55w, Off
(still plugged in.): .85w
Older HP 1702: Max: 40w, Typical: 28.5w, Power Save: 2w.
I don't really want to do a weighted sum of monitors and power
usage. I think going with telling people "25 watts saved per monitor
as a conservative estimate", or "roughly 100 MWH per year,
conservatively", is the right thing.
-wdc
On Jul 29, 2008, at 4:38 PM, Jonathon Weiss wrote:
>
> This got me to thinking "this will probably save enough power to
> actually be interesting, won't it?" to answer that question for
> myself and other's I present some numbers.
>
> Assume you can save 25W by sleeping an average Athena LCD monitor (I
> beleive this is a conservative estimate, and the actual number will be
> more like 30 or 35).
>
> Multiply by 1000 Athena workstations (Actually 984 in the July status
> report, but 1000 is really easy to multiply): 25kW
>
> Assume that the average monitor will be sleeping 10 hours a day/night
> (I think this is very conservative, especially since it assumes
> weekends are regular days, but again it is easy to multiply): 250kWH
>
> 365 days/year: 91.25 MWH/year.
>
> http://cogen.mit.edu/powermit/ estimates that N* bills MIT $58.77/MWH
> (though this number appears to be 5 years old, and is probably a
> low-ball estimate now): $5363/year
>
> If we assume 35W savings and 14 hours a day of sleeping monitors
> (which is certainly more agressive, but not unbelievable):
> 490kWH/day
> 178.85MWH/year
> $10511/year
>
> Realistically, I'd guess that we'll fall between the two. Either way,
> it seems worth pursuing.
>
> Jonathon
>
