[comp.sys.sun] Screens: to shut off or not to

berlin%bu-albert.BU.EDU@bu-it.bu.edu (David Fickes) (12/21/88)

Has anyone actually asked Sun whether we should shut down our display
screens at night or on the weekends?  We tend to have several machines
idle for a couple of days at a time and I've been wondering.  Currently,
we just scrlock them.

[[ Certainly you should take measures to save the phosphor in them.
Running screenlock should be sufficient for this.  It just needs to be
something that changes periodically so that no one image gets a chance to
get "burned in".  I understand that turning them off and back on actually
puts quite a bit more "stress" on the components than just leaving them on
overnight, thus reducing the monitor's lifetime.  Of course, this could
just be an urban legend---I have no solid sources or research to back this
up.  --wnl ]]

- david

David K. Fickes				            dfickes@bu-albert.bu.edu
The Collected Papers of Albert Einstein    ...harvard!bu-it!bu-albert!dfickes
Princeton University Press / Boston University            berlin@buita.bu.edu
745 Commonwealth Avenue - room 541		617/ 353-9249
Boston, MA 02215  				617/ 783-4301

zjat02@uunet.uu.net (Jon A. Tankersley) (01/13/89)

Depending on the type of Monitor, it is better to turn it off and back on
every weekend/night.  The Ikegami(sp) had a poor MTBF rating for the power
supply and a not much better one for the Monitor itself.  We had Ickky's
dying after about a year because we left them on with screenlock running.
Now we turn them off a night and on weekends.  Screenlock is run when
user's log off and a screenblank like substitute is being written to blank
and lock idle screens after so many minutes....

-tank-
-- 
#include <disclaimer.h>		/* nobody knows the trouble I .... */

"Bruce_Hamilton.OsbuSouth"@xerox.com (01/25/89)

I'd like to share some knowledge and ask if anyone has done cost studies
on powering down entire Sun processors (not just the displays).

I can't speak to the various models of Sun, but at Xerox a couple of years
ago, we did some cost studies and controlled experiments in powering off
our own Xerox model 8010 and 6085 workstations.  We discovered

-yes, there is SOME "infant mortality" at the board level when you start
cycling power each day on machines which used to stay on all the time

-however, the total savings in power is HUGE.  A buck a night power saved
per workstation times an installed base of about 20K workstations gets
into the megabucks REAL FAST.

Conclusion: except for the very oldest model 8010's with a separate disk
box, which tends to throw a drive belt on power-up, we recommend powering
down everything except public server machines each night.

I'd be surprised if the conclusions were much different for Sun machines,
since to a first approximation, electronics is electronics (power usage
vs.  MTBF under various conditions of cycling power).

--Bruce
CSNet: Hamilton.osbuSouth@Xerox.COM
UUCP: xerox.com!hamilton.osbuSouth
213/333-8075

jeremy@kheops.cmi.no (Jeremy Cook) (02/03/89)

>-yes, there is SOME "infant mortality" at the board level when you start
>cycling power each day on machines which used to stay on all the time
>-however, the total savings in power is HUGE....

Ah yes but equipment budgets are quite different from overheads. I doubt
if one could convince the administration to give some of the money saved
on electricity to pay for repairs!

-- Jeremy Cook