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From: smh@mhuxu.UUCP (S. M. Henning)
Newsgroups: sci.electronics,misc.consumers
Subject: Re: When should a PC be turned off ?
Message-ID: <7856@mhuxu.UUCP>
Date: 22 Jul 88 20:24:31 GMT
References: <3226@tekgen.BV.TEK.COM>
Organization: AT&T Bell Laboratories, Murray Hill
Lines: 26

In article <3226@tekgen.BV.TEK.COM>, steves@tekgen.BV.TEK.COM (Steve Shellans) writes:
 
> To maximize their life expectancy, when should they be turned off?
> At the end of every day?  For weekends only?  Only when they will
> be out of use for a week or more?   Never??
> 
> (As I understand it, the issue is as follows.  Electronic components
> suffer most of their wear when they are powered-up.  Therefore, the
> longest life can be realized by never turning them off.  Exception --
> damaging power surges.  On the other hand, mechanical components, such
> as hard disk drives, wear out as a function of total hours of use.)

The limiting factor in Penna is not component life but lightning strikes.
Perhaps in Oregon, this is not a major factor most of the year, but here
it is either lightning or ice/snow storms which cause gross power fluctuations
which crash hard disks.  The rule of the thumb I use is that if there is
a chance I will not be able to get back to my equipment in case of a
storm, I will shut everything down.  The only component which has a finite
life and doesn't like power up is the crt.  The other components basically
should be left on during periods of use and shut off during periods when 
not used like over night and weekends.  Many people leave their hard disks
on all the time but they risk crashes and eventually wear out the mechanical
parts.

****                    Lang May Your Lum Reek                      ****
Steve Henning, AT&T Bell Labs, Reading, PA           UUCP: att!mhuxu!smh