Path: utzoo!utgpu!news-server.csri.toronto.edu!rutgers!ucsd!sdd.hp.com!decwrl!sgi!shinobu!odin!moose.asd.sgi.com!jwag
From: jwag@moose.asd.sgi.com (Chris Wagner)
Newsgroups: comp.sys.sgi
Subject: Re: About SMD's and IPI's, again.
Message-ID: <1990Sep6.203828.15588@odin.corp.sgi.com>
Date: 6 Sep 90 20:38:28 GMT
References: <1990Sep6.081301.1179@sgzh.uucp>
Sender: news@odin.corp.sgi.com (Net News)
Reply-To: jwag@moose.asd.sgi.com (Chris Wagner)
Organization: Silicon Graphics, Research & Development
Lines: 48

In article <1990Sep6.081301.1179@sgzh.uucp>, root@sgzh.uucp (Bruno Pape)
writes:
> In response to my recent posting about the differences between the 1.2GB
> SMD and IPI drives I received the following two replies from people at
> SGI Mountian View.
> 
>
-------------------------------------------------------------------------------
> 
> as far as i can tell, all you need to do is change the controller
>   and the cables.  I believe the drive will stay the same
> 
> It's a Sabre V
> 
>
-------------------------------------------------------------------------------
> 
> SMD and IPI drives look the same, but are actually quite different.  The only
> areas which might be similar are the power supplies, but I don't know for
> sure.  In general, we are treating them as completely different drives, much
> as we treat a 780 and 380 from the same manufacturer differently.
> 
>
-------------------------------------------------------------------------------
> 
> Would someone like to submit a third opinion?  I could use it as a tie
breaker,
> if it is not radically different.
> 
> Do we know what we will need to do to upgrade a machine with SMD disks to
> IPI disks?
> 
> How about spare parts numbers for IPI disks and controlers?
> 

Ack!! Is a SCSI and an ESDI drive the same cause they are both 5 1/4"
form factor??

No, SMD and IPI are in no way similar except that they are both 8" form factor
(and may share some common manufactured components). Most importantly
the disk data protocol is completely different (serial instead of parallel)
so cables etc are not the same. Second the IPIs are parallel head while the
SMD are not, etc.etc.etc.

The only way to 'upgrade' is to remove your SMD controller, drives, cables
and installa new controller, drive, cables

Chris