[6163] in Release_7.7_team
Re: Athena Video Monitor Power Save information for outreach articles.
daemon@ATHENA.MIT.EDU (William Cattey)
Tue Jan 13 13:48:52 2009
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Cc: Jonathon Weiss <jweiss@mit.edu>, release-team@mit.edu,
"Rao, Laxmi J" <lrao@mit.edu>
From: William Cattey <wdc@MIT.EDU>
Date: Tue, 13 Jan 2009 13:47:19 -0500
To: Robyn Fizz <fizz@mit.edu>
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Summary:
1. Please say, "enabled power save mode" rather than "disabled screen
saver".
2. "watts" without a per hour or any such thing is correct.
3. The change affects ALL Athena desktop systems not just the 375 or
so in clusters.
4. Identifying broken Athena machines will be done by using existing,
and some new remote monitoring tools, so trips to the clusters to
check on systems will be largely eliminated.
Suggested amendment to your draft (sorry for using plain text):
---- Begin Draft 3 ----
Historically, the video displays of Athena workstations never shut
off. A screen saver with the Athena logo indicated an up-and-running
system, while a blank screen meant a broken system. An operator could
identify dead machines just by glancing into the room. When power
saving became standard practice, Athena disabled the power-save
feature, fearing that people would be too used to the Athena
convention of blank monitor = broken workstation.
However, the power consumed by even a low-power LCD display is
significant – about 25 watts per monitor when idle but not in power
save mode. To save energy and reduce costs, IS&T recently made the
decision to re-enable the power-save feature. This change will save
in excess of 90 MegaWattHours of electricity costing about $10,000
per year, (assuming 25 watts per system, 900 systems, 10 hours idle
time per day, and electricity cost of $0.11 per KiloWattHour.)
The change to enable monitor power save mode was deployed on January
13, 2009. IS&T hopes that Athena users will realize that a blank
Athena screen no longer signifies a broken computer, but instead
means that Athena has “gotten with the program.” Athena monitors now
behave like standard monitors and may need a move of the mouse or the
strike of a key to wake up.
System operators, rather than visiting the systems, will use remote
monitoring to detect dead systems.
---- End Draft 3 ----
Further clarification:
Re: Screen saver:
It is inaccurate to say that we have turned off the screen saver. We
haven't. In fact there are two different screen savers, one that
wakes up on a logged in system when the user is idle, and one that
wakes up when nobody is logged in. (Actually this is exactly the same
thing you see on other computers. After X minutes the screen saver
runs. After X + Y minutes, power save runs and turns off the monitor.
The most accurate description of the change is that the power saving
option for the X window system previously disabled on Athena has now
been enabled.
Re: Power consumption:
"25 watts" is the correct unit of energy consumption. That is 25
joules of energy every second. Just like a light bulb. A typical
Athena monitor burns 25 watts to show a static image. Consumption
can go up to 35 watts if the image is changing a lot. Typical power
save mode consumes under one watt.
Re: Savings:
25 watts multiplied by 900 monitors multiplied by 10 hours of power-
save time per day multiplied by 365 days in a year is 82,125,000 Watt
Hours per year.
MIT's electricity cost is estimated at 11 cents per kilo-WattHours,
so savings would be 82,125 kilo-WattHours multiplied by $0.11 per
kilo-WattHour or $9033.75 per year.
On Jan 13, 2009, at 11:39 AM, Robyn Fizz wrote:
> Hi Bill,
>
> I've attached a revised news article for your review.
>
> I think in your original you went with 900 systems, so please let
> me know the final number you'd like to go with. Also, please note
> the questions about hours and how operators now figure out when
> workstations are broken.
>
> Regards,
> Robyn
>
> At 6:08 PM -0500 1/12/09, William Cattey wrote:
>> The reason why I went with 800 systems was that I wasn't sure how
>> many of those 950 were desktops, and how many were servers that
>> wouldn't be affected by the change.
>>
>> -Bill
>>
>> On Jan 12, 2009, at 6:07 PM, Jonathon Weiss wrote:
>>
>>>
>>> Hi Bill,
>>>
>>> I actually had a similar conversation with Laxmi this afternoon
>>> when I
>>> ran into her. I dredged up some of our old research and came up
>>> with:
>>>
>>> Assume 25W/monitor savings (conservative)
>>> Assume 1000 workstations (actually 956 according to Dec. stats)
>>> Assume 10 sleeping hours per day (conservative)
>>> Assume 365 days per year :-)
>>> Estimated power savings: 91.25MWh
>>> Using Laxmi's (conservative) blended average cost to MIT of $0.11/
>>> kWh
>>> Estimated cost savings: $10037.05/year
>>>
>>> Of course, we really only have 1-2 significant digits, but we can
>>> reasonably say $10K/year!
>>>
>>> Even if we go with 950 workstations (which I don't think is strictly
>>> required, since we wen't conservative on every other number
>>> there) it
>>> ends up at $9500/year, and cover 85MWh.
>>>
>>> Jonathon
>>>
>>>
>>>> Robyn,
>>>>
>>>> Thanks for the chat today, and for offering to help to get the word
>>>> out. Here is a first draft of everything that could be said.
>>>> Perhaps you can suggest some amendments to say it more succinctly.
>>>>
>>>> ---- Begin draft ----
>>>>
>>>> On Tuesday January 13, 2009, Athena on Linux and Solaris enabled
>>>> power save mode on its video monitors.
>>>>
>>>> Historically, Athena never shut off the video display. A screen
>>>> saver
>>>> with the Athena logo enabled an operator to identify dead machines
>>>> just by glancing into the room. A blank screen meant a broken
>>>> system. When power saving became standard practice, Athena
>>>> disabled
>>>> the power save feature, fearing that people would be too used the
>>>> Athena convention, "blank monitor means dead Athena Workstation".
>>>>
>>>> The power consumed even by a low power LCD display is significant:
>>>> We expect to save in excess of 75 MegaWattHours of electricity per
>>>> year. (25 watts per monitor, 10 hours idle time, 900 systems, 365
>>>> days.)
>>>>
>>>> We hope that Athena users will realize that a blank Athena
>>>> screen no
>>>> longer means a broken computer, but instead means Athena has
>>>> finally
>>>> "gotten with the program" -- that our monitors behave like standard
>>>> monitors and may need a move of the mouse or the strike of a key to
>>>> wake up.
>>>>
>>>> ---- End Draft ----
>>>>
>>>> -Bill
>>>>
>>>> ----
>>>> Important: IS&T IT staff will *NEVER* ask you for your password,
>>>> nor
>>>> will MIT send you email requesting your password information.
>>>> Please
>>>> continue to ignore any email messages that claim to require you to
>>>> provide such information.
>>>> ----
>>>>
>>>> William Cattey
>>>> Linux Platform Coordinator
>>>> MIT Information Services & Technology
>>>>
>>>> N42-040M, 617-253-0140, wdc@mit.edu
>>>> http://web.mit.edu/wdc/www/
>
>
> --
> Robyn Fizz
> News Coordinator
> MIT Information Services and Technology (IS&T)
> N42-290B
> Phone: 617 253-0540
> Fax: 617 258-6875
>
> Important! Do not give out your passwords!
> IS&T will *never* ask for passwords or other personal information
> via email.<AthenaScreenSaver2009.doc>
