dr@skivs.UUCP (David Robins) (04/26/89)
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 -- David Robins, M.D. (ophthalmologist / electronics engineer) The Smith-Kettlewell Institute of Visual Science, *** net: uunet!skivs!dr 2232 Webster St, San Francisco CA 94115 *** 415/561-1705 (voice) The opinions expressed herein do not reflect the opinion of the Institute!
jimb@hpmcaa.HP.COM (Jim Belesiu) (04/27/89)
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 Belesiutims@starfish.Convergent.COM (Tim Simmons) (04/28/89)
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
swh@hpcupt1.HP.COM (Steve Harrold) (04/28/89)
Re: Turning off hard-disk motor To answer the needs of your weather station application: If the rate of disk access is so low, have you considered writing the hourly material to a floppy drive instead (which stops rotating shortly after the write operation)? That way you can reduce the cost of your PC by totally deleting the hard disk. From my own experience, I've run 2 HP Vectra ES (AT-compatible) machines for over 2 years, on a daily basis, with a power shutdown at the end of every day. Result: NO hard disk failures.