Subject: Re: EIDE -> SCSI adapter
To: None <current-users@NetBSD.ORG, fair@clock.org>
From: Matthew Jacob <mjacob@feral.com>
List: current-users
Date: 05/16/1997 22:56:48
>From: "Erik E. Fair" (Timekeeper) <fair@clock.org>
>Subject: EIDE -> SCSI adapter
>...
>I have been watching the prices in the EIDE market drop, and today's
>announcement from IBM about two new drives for laptoys (4GB and 5GB) for about
>$0.11 per megabyte (list!) makes me wonder: how hard would it be to make an
>EIDE -> SCSI adapter (similar to the Emulex MD21 thingy that Sun used to use
>to make ESDI look like SCSI), and does one exist for sale now?
>
>Or is there no point to such a beast?
>
>	Erik E. Fair	fair@clock.org
>

Ah, speaking of MD21's- I have a pile. Want one? To add the the
pile of old boards- like Joel's SMD controller?

At any rate, there are still a couple of problems you'd
need to solve:

	a) with EIDE, you don't get bad block remapping- you
have to do that manually. You also don't get the kind of
multiple command and cacheing you get with SCSI drives.

	b) The mfg cost of SCSI to multiple EIDE is probably
more than the equivalent cost of embedding SCSI controllers
onto the drives. Anyone out there doing raw parts pricing want
to comment?


A much more interesting question to me is what will happen to
the *very* large RAID boxes. It strikes me that with all the
h/w infrastructure that the EMC && MAXSTRATs of the world have
that perhaps a RAID implementation with internal rows of EIDE
might be an interesting thing.