Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!tut.cis.ohio-state.edu!ucbvax!ucsd!sdcsvax!ucsdhub!hp-sdd!hplabs!hp-pcd!hpmcaa!jimb
From: jimb@hpmcaa.HP.COM (Jim Belesiu)
Newsgroups: comp.sys.ibm.pc
Subject: Re: Turn-off Harddisk Motor?
Message-ID: <200024@hpmcaa.HP.COM>
Date: 26 Apr 89 19:30:44 GMT
References: <2826@skivs.UUCP>
Organization: HP McMinville Division
Lines: 18

I don't believe there is a software command to turn standard PC disk drives
off but...

As I understand it, the most wear a hard disk drive experiences is during 
the spin-up spin-down phase of powering the drive on and off.  So I would
recommend to leave the drive spinning.

As a point of reference, our division has approximately 150 HP Vectra ES and
RS machines ('286 and '386 PC-AT types).  The engineers have about half of the 
machines and we leave them running 24 hours a day.  The marketing, accounting, 
and purchasing people have the other half of the machines and they like to
turn them off at night.  Most of the machines are two to three years old.

So guess who has the greater frequency of disk drive failures - the group
that turn their machines off nightly.  I personally have had one computer
spinning for three years and another for 8 months without a disk drive failure.

Jim Belesiu