Screens: to shut off or not to

["Bruce_Hamilton.OsbuSouth" at xerox.com]

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 at Xerox.COM
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