Re: (OT) Storage (8*IDE HDs) any experiences?
On Sun, Apr 29, 2001 at 10:14:35AM +0200, Russell Coker wrote:
> On Sunday 29 April 2001 06:48, Brandon High wrote:
> > On Sat, Apr 28, 2001 at 11:50:26PM +0200, Andreas Bombe wrote:
> > > The IBM SCSI disk I have here has a jumper to delay spin up depending on
> > > SCSI ID so that an array of those would spin up sequentially if they all
> > > had those jumper set (and different IDs, which they need anyway). Maybe
> > > there are IDE drives built with RAIDs in mind offering some similar
> > > option?
> >
> > I doubt it, but with a sufficiently large case (or small power supply) it
> > may be possible to stick a 2nd (or 3rd) power supply in. Drives could be
> > plugged into the second PS while the MB is powered off of the primary PS.
>
> That sounds like a really bad idea to me.
>
> In a regular setup the IDE controller and the drive get power from the same
> source. So if the signals on the cable have more current going one way than
> the other then the difference will be made up on the 0V line on the PSU. If
> you have separate PSU's then the difference will go through other lines of
> the data cable. This is something that is likely to be fatal to drives and
> motherboards.
>
> But if you try it please let me know how it works. ;)
A good solution for this might be to connect the first PS's output to the
other, so the voltage is the same, and there's no massive current flow across
the data cables.
Anyone desagrees to this?
--
Pedro Larroy Tovar. PiotR | http://omega.resa.es/piotr/
piotr@logiccontrol.es
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