From: Tim Shoppa <shoppa@alph02.triumf.ca>
Message-Id: <9803010445.AA18387@alph02.triumf.ca>
Subject: Re: CD-ROM from SCO unlikely
To: sms@moe.2bsd.com (Steven M. Schultz)
Date: Sat, 28 Feb 1998 20:45:51 -0800 (PST)
Cc: pups@minnie.cs.adfa.oz.au
In-Reply-To: <199802280443.UAA00780@moe.2bsd.com> from "Steven M. Schultz" at Feb 27, 98 08:43:41 pm
Content-Type: text
Sender: owner-pups@minnie.cs.adfa.oz.au
Precedence: bulk

> > Incidentally, a couple of weeks ago I made a nice bootable Iomega ZIP
> > cartridge with the current 2.11 generic kernel and everything in /usr.  It all
> > barely fits in the 100 Mbytes (well, 3*65536*512 bytes) available, and
> 
> 	How "speedy" is a ZIP drive?

In case anyone is interested in the benchmarks, here's a short summary:

Both a Webster ESDC (1 Megabyte cache, Hitachi DK512-12 ESDI drive) and
an Andromeda SCDC (2 Mbyte cache connected to many SCSI devices, including an
"internal" SCSI ZIP) are present on my main development machine, a 11/73
(KDJ11-B) with 2 Mbytes of non-PMI memory.  Caching on both controllers
was enabled and two benchmarks were done with each disk subsystem.  Times
reported below are "wall times".  All of this is done under the latest
release of 2.11BSD using a non-networking system and no other work
being done on the system.

1.  "make sendmail" took 1159.4 seconds on the WQESD+Hitachi, and 1165.3
    seconds on the SCDC+ZIP.

2.  "find /usr -print > /dev/null" took 166.4 seconds on the WQESD+Hitachi
    and 165.0 seconds on the SCDC+ZIP.

It looks like, for most purposes, the ZIP on a good SCSI host adapter is
just as good as an ESDI drive on a good ESDI controller.  I think
Steven was expecting to see a substantial hit due to the ZIP's access time,
but I think that the buffering in the host adapter and in the ZIP drive
itself makes this a minor concern.

Tim.