Path: utzoo!utgpu!watserv1!watdragon!lion!mefarimani
From: mefarimani@lion.waterloo.edu (Mehran E. Farimani)
Newsgroups: comp.sys.ibm.pc
Subject: Re: Dusty Dorms. WAS: Re: Computer on 24hrs.day? (yes or no)
Message-ID: <23072@watdragon.waterloo.edu>
Date: 10 Apr 90 00:13:28 GMT
References: <1976@crash.cts.com> <1649@watserv1.waterloo.edu>
Sender: daemon@watdragon.waterloo.edu
Organization: University of Waterloo
Lines: 32

In article <1649@watserv1.waterloo.edu> ssingh@watserv1.waterloo.edu ($anjay [+] $ingh - Indy Studz) writes:
>
>By how much is the life of the components being shortened if you turn
>it on, on average, twice a day?
>
It is hard to comment on "how much" the life is shortened. Electronic 
components have a life-time with exponential distribution, which means that
aging has no deterministic effect on their future performance (supposedly,
it has no effect at all). 

However, frequent power-ups result in aging of the connections and also the
electronic components themselves. So, as far as the electrical parts of a 
machine are concerned, frequent power-ups are not a good idea.

Nevertheless, leaving the machine running continuously does have effects
on the mechanical parts of your computer, specifically your hard drive.

Hard drives have an expected life-time which is usually measured by the 
number of disk spins. This is, generally, quite a large number. However,
leaving your machine running continuously reduces this as the disk is 
spinning constantly. 

A general rule of thumb is that  if you are going to power-up your 
computer more than once in a day, then don't bother turning it off.
One power-on per day keeps a reasonable balance between the two sides
of the story. However, make sure you have a reliable surge protector
since, by leaving your computer on for a longer period, you are increasing
your chances of being hit by a power surge.

Hope this helps.

Mehran