Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!mailrus!ames!oliveb!pyramid!ctnews!starfish!tims
From: tims@starfish.Convergent.COM (Tim Simmons)
Newsgroups: comp.sys.ibm.pc
Subject: Re: Turn-off Harddisk Motor?
Message-ID: <997@starfish.Convergent.COM>
Date: 27 Apr 89 21:51:03 GMT
References: <2826@skivs.UUCP>
Organization: Convergent Technologies, San Jose, CA
Lines: 21

From article <2826@skivs.UUCP>, by dr@skivs.UUCP (David Robins):
> Is it possible to turn-off (power-down) the motor on an AT hard disk
> drive, by software (preferable) or hardware?
> 
> A friend has a weather recording station, and much of the time is
> spent idle.  Once and hour, data is written to disk.  It seems a shame
> to waste the MTBF hours of the drive.  He would like to turn it off,
> and turn-on only when ready to save data.
> 
> All replies welcome!		-dave

Dave,

It is actually much better for a hard drive to keep it running.
The spin-up/spin-down period causes 98% of the wear to both head
and disk.  By the way MTBF is calculated assuming that the drive is
running 24hrs a day, 7 days a week.  Most drives have an MTBF of at
least 30,000hrs, while the motor has an MTBF of about 120,000
hours.  So.... it makes much more sense to leave the thing on.

tims@starfish.Convergent.COM