Which should be Master/Device 0: HD or OD?

Archived from groups: alt.comp.hardware.homebuilt (More info?)

I have been wondering lately, as the topic has come up elsewhere:

What Device should run as the Master/Device #0 and what device should the
the slave/Device #1 on a Parallel ATA-EIDE channel when one wants to pair
up a hard drive and an optical drive?

Some people, of late, have been suggesting that the *Optical Drive* be put
in the Master position, particularly *if* that optical drive is a DVD. Why
would that be?

Other than logical position assignment, what is involved in the
Master/Slave issue, and why choose one and not the other?

Also, is there any advantage or speed increase if one has the drives set
both via cable position *and* jumper assignment (EG, setting an optical
drive as MA (master jumpered) and also putting it on the Master position of
the cable)?

This has always been a question for me but I have always assumed (wrongly?)
that this is a total non-issue, and that convenience should dictate.
But... Hard drives have larger Caches, so shouldn't they be Master's? To
set them as Master means real cable bending though, so what is one to do?

TIA!
1 answer Last reply
More about which master device
  1. Archived from groups: alt.comp.hardware.homebuilt (More info?)

    On Fri, 06 May 2005 03:17:55 GMT, signmeuptoo
    <signmeuptoo_no_spam@earthlink.net> wrote:

    >I have been wondering lately, as the topic has come up elsewhere:
    >
    >What Device should run as the Master/Device #0 and what device should the
    >the slave/Device #1 on a Parallel ATA-EIDE channel when one wants to pair
    >up a hard drive and an optical drive?


    It does not matter. It never did matter.
    There was a time, about 12 years ago, when pairing an UDMA
    drive with a PIO optical drive would degrade performance.
    Since then there has been no difference no matter what the
    hardware.

    >
    >Some people, of late, have been suggesting that the *Optical Drive* be put
    >in the Master position, particularly *if* that optical drive is a DVD. Why
    >would that be?

    Because any nut can click a mouse and think that makes them
    knowledgeable about topics beyond (clicking a mouse)?
    That's what windows does, it makes people feel competent at
    computers. Indeed it DOES make them competent, but at only
    a narrow subset out of a broad expanse.


    >
    >Other than logical position assignment, what is involved in the
    >Master/Slave issue, and why choose one and not the other?

    Cable routing. Modern drives use ATA66 or higher more often
    so an 80 conductor cable is used. The easy answer is then
    to make the device at the end of the cable (after routing
    the cable the easiest way possible) the master.


    >
    >Also, is there any advantage or speed increase if one has the drives set
    >both via cable position *and* jumper assignment (EG, setting an optical
    >drive as MA (master jumpered) and also putting it on the Master position of
    >the cable)?

    No, but you should do both, OR set the drive to cable
    select, either way. It only designates the logical # of the
    drive initially not any other performance parameters.


    >
    >This has always been a question for me but I have always assumed (wrongly?)
    >that this is a total non-issue, and that convenience should dictate.
    >But... Hard drives have larger Caches, so shouldn't they be Master's?

    No, the cache is localized, ONLY that drive can use it and
    thus it is not associated in any way with (anything, there
    is no possible external factor that matters in this regard).


    >To
    >set them as Master means real cable bending though, so what is one to do?


    Don't ever try to make any particular device Master.
    Instead, pair any two drives most-often simultaneously used,
    on different IDE channels... matters not if they're master
    or slave, only that they're on different channels. Even
    this is far less important than it used to be, back when
    drives were ATA33 rather than ATA66/100/133.
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