[comp.sys.ibm.pc.misc] leaving PC on

streib@silver.ucs.indiana.edu (Allan Streib) (08/02/90)

I have an PC-XT clone w/20meg hard drive which I leave on 24 hrs a
day.  I feel that this is not harmful to the PC itself, but what about
the hard drive?  Any opinions, out there?

Thanks-

--
Allan (streib@silver.ucs.indiana.edu)

medici@dorm.rutgers.edu (Mark Medici) (08/02/90)

streib@silver.ucs.indiana.edu (Allan Streib) writes:

>I have an PC-XT clone w/20meg hard drive which I leave on 24 hrs a
>day.  I feel that this is not harmful to the PC itself, but what about
>the hard drive?  Any opinions, out there?

This has been the subject of much philosophical and technical debate.
However, speaking strictly from personal experience, I have had only a
single failure of all systems (mechanical or electronic) left powered
on 24hr/day.  That failure was DAC (digital-analog convertor) in the
video output circuit on an IBM PS/2 Model 80 motherboard, which was
probably defective from the start.

My experience includes 5 LAN servers running 24hr/day for 3 years, a
BBS on an original IBM PC/XT with Segate ST225's, and my personal
PC/AT with 100MB RLL drive.  Only one of these systems has a UPS,
though all have surge/spike protection.

However, I do recommend:

  -  Turn off your display and printers when they will not be used
     for extended periods.
  -  Ensure that your system is installed where it is not subject
     to excessive vibrations, dust or heat.
  -  Physically disconnect it from power and phone lines (especially
     phone lines) during local lightning activity.  Got a fried modem
     this way, once.
  -  Use some form of power protection (e.g., surge/spike protector,
     or better yet, a UPS).

Of course my personal experiences may deviate from averages.  Good luck.

hart@blackjack.dt.navy.mil (Michael Hart) (08/07/90)

In <Aug.2.10.30.45.1990.11726@dorm.rutgers.edu> medici@dorm.rutgers.edu (Mark Medici) writes:

>streib@silver.ucs.indiana.edu (Allan Streib) writes:

>>I have an PC-XT clone w/20meg hard drive which I leave on 24 hrs a
>>day.  I feel that this is not harmful to the PC itself, but what about
>>the hard drive?  Any opinions, out there?

>[stuff deleted]

My $.02 worth -- remember, though, you get what you pay for!!
Your mileage may vary.

I worked for 13 years as a computer field engineer.  This question has been
asked by everyone responsible for the running of any computer worth more than
87 cents.

I refer you to the "light bulb law".  That law being: When do light bulbs
burn out??  _when you turn them on_  There is a large surge of current through
the device; energy where there was none, etc.  Kinda like being woken up by
a bucket of water in the face!  Most of the engineers (real, degreed) I've
spoken to told me the worst thing you can do to a machine is turn it on.
But, once it's on, LEAVE IT ON!

>My experience includes 5 LAN servers running 24hr/day for 3 years, a
>BBS on an original IBM PC/XT with Segate ST225's, and my personal
>PC/AT with 100MB RLL drive.  Only one of these systems has a UPS,
>though all have surge/spike protection.

>However, I do recommend:

>  -  Turn off your display and printers when they will not be used
>     for extended periods.
=====^^^^^^  Absolutely!  No reason to kill your monitor.  Modify as
needed, if you have a reliable screen saver.


>  -  Ensure that your system is installed where it is not subject
>     to excessive vibrations, dust or heat.
>  -  Physically disconnect it from power and phone lines (especially
>     phone lines) during local lightning activity.  Got a fried modem
>     this way, once.

I've never had a storm induced problem.  Use your own knowledge of how the
power utility is in your area.  Tho, if  you're worried, unplug it.  I knew
someone who unplugged _EVERY_ electric appliance in the house when it rained!!


>  -  Use some form of power protection (e.g., surge/spike protector,
>     or better yet, a UPS).

^^^^^^^^^^^ _ABSOLUTELY_  When you spend Multi-Thousands of your hard earned
$$$$$$ on a machine, be smart enough to spend another $150 or so for either
a good power conditioner, or small UPS.


--
-------------------------------------------------------------------------------
Michael G. Hart   hart@blackjack.dt.navy.mil /  mhart@dtrc.dt.navy.mil
DTRC/DoD			  |  "Wherever you go, there you are."- me
DISCLAIMER: If you want the Navy's opinion, talk to Secretary Cheney.

kabra437@pallas.athenanet.com (Ken Abrams) (08/09/90)

In article <hart.650028982@blackjack> hart@blackjack.dt.navy.mil (Michael Hart) writes:
>
>>>I have an PC-XT clone w/20meg hard drive which I leave on 24 hrs a
>>>day.  I feel that this is not harmful to the PC itself, but what about
>>>the hard drive?  Any opinions, out there?
>
[Quotes and quoted quotes deleted]
>
>I refer you to the "light bulb law".  That law being: When do light bulbs
>burn out??  _when you turn them on_  There is a large surge of current through

Even though most of the components in a PC are NOT light bulbs ( and don't
behave like one either), I would agree with you that leaving it on is best
if the ONLY consideration was hardware reliability (and it is connected to
a stable power source).  As I see it, however, hardware reliability is not
the only issue and a case can be made for the theory that a properly designed
disk drive will wear out from heat and friction and dirt before it will
suffer any electrical damage from being started and stopped once a day.
I think that all the energy wasted by millions of PCs left on 128 hours a
week when they are not being used is a bigger and more important issue than 
whether or not it will extend your repair cycle from 3 years to 5 years.
There is also a small extra potential for a fire in a running device.

I have been in the computer industry for close to 25 years, mostly as a
technician.  I have weighed all the arguments and I have decided to turn
MY machines off when they will not be needed for 6 hours or more.  I even
turn the Xenix box off over the weekends.  

Like a lot of other things in modern life, this is not strictly a technical
call but it has some moral undertones too.   Make your own call but don't
overlook part of the factors in the process.

-- 
========================================================
Ken Abrams                     uunet!pallas!kabra437
Illinois Bell                  kabra437@athenanet.com
Springfield                    (voice) 217-753-7965