Subject: REVIEW: Seagate ST3655N SCSI hard drive
From: [email-masked] (Andre Yew)
Date: 1 Jan 1994 19:07:53 GMT
Newsgroups: comp.sys.amiga.reviews

PRODUCT NAME

	Seagate ST3655N SCSI hard drive

	[MODERATOR'S NOTE:  This review was updated on Jan 18, 1994.
	Search for the text "[UPDATE:" to find updated information.
	-Dan]

BRIEF DESCRIPTION

	The ST3655N is a 540-megabyte SCSI hard drive that formats
to 519 MB.

AUTHOR/COMPANY INFORMATION

	Name:		Seagate Technology, Inc.
	Address:	920 Disc Drive (really, that's the name)
			Scotts Valley, CA 95066
			USA

	Telephone:	(408) 438-8222
	FAX:		(408) 438-2620

LIST PRICE

	The list price is well over $1000 (US), but it's irrelevant to the
actual street price.  I paid $621 with Federal Express standard overnight
shipping from Hard Drives International, a mail order company that
advertizes in Computer Shopper.

SPECIAL HARDWARE AND SOFTWARE REQUIREMENTS

	HARDWARE

		You need a SCSI host adapter.

	SOFTWARE
	
		None.

MACHINE USED FOR TESTING

	Amiga 3000/25, with 2 MB of Chip RAM and 8 MB of Fast RAM.  This
machine has the PROTO version of the Western Digital 33C93 SCSI chip.

	Softkicked version 37.175 Kickstart, and version 38.35 Workbench.

	Original 52 MB Quantum hard drive, cached with HyperCache Pro.
	
	XFH 1.3 filesystem compression used on several directories.

INSTALLATION

	The hard drive was very easy to install.  This is covered in more
detail in the review, since installing a drive is half of buying and using
one.

	DISCLAIMER:  I wrote this review mostly as a guide for people who
wanted to install hard drives in their A3000s.  However, remember that you
are dealing with CMOS devices and you should properly ground yourself before
touching the drive or opening up your computer.  This means you should
either wear a grounding strap connected to ground, or touch the case of your
power supply or another grounded metallic object periodically when you
work.  If you damage anything because of this review, it's your fault for
not preparing adequately.

	Also be aware that Commodore might still take a dim view of people
opening up their computers, and might cancel your warranty because of it.
This happened to me, so it can happen.

REVIEW

	I decided to move out of the Dark Ages of computing recently when I
bought a new hard drive to supplement the A3000's original 52 MB Quantum
drive.  I decided that I was going to do this right, since it was the only
upgrade I was going to do for a while.  With that goal in mind, I wanted a
big and fast drive. What I ended up with was certainly big --- half a
gigabyte --- but not the fastest drive in its class.

	I purchased the drive through mail order from Hard Drives
International.  They were courteous and helpful, but a little clueless.  I
asked that the drive be shipped to my office, but instead it was shipped to
my home.  Perhaps it was because I caught them right before Christmas.
Anyway, the drive arrived, and I had it installed and running in less than
20 minutes.  Here's what I did.

	[MODERATOR'S NOTE:  If you are not comfortable opening up your
	Amiga, then you should have the work done by an authorized Amiga
	service center.  Opening your Amiga yourself may void your warranty,
	and careless work may even damage the machine.  - Dan]

	First, I read the documentation, which is extremely biased towards
PC clones with its DOS setup section and all.  The most important part of
the documentation is the section explaining the jumpers.  The are two things
that need to be configured on the drive:  the SCSI ID number and the
termination.  Every SCSI device on the same wire must have a unique SCSI
ID.  Since the Quantum already had ID #6, and host controllers tend to have
ID #7, I picked 5.  Next, since I was not using the drive in Fast SCSI mode,
I picked passive termination.  The jumpers for the termination blocks were
stubborn and could be removed only by a very fine pair of pliers.

	That done, I had to reconfigure the Quantum.  Because of transmission
line effects, the SCSI devices at the ends of the wire must be terminated
with resistors that match the impedance of the wire.  This is to fool the
signal on the wire into thinking that the wire is really infinitely long,
(since it just sees the same impedance all around) so it can't reflect.
In theory, since the drives are connected in parallel, you would need to
have only two devices on the line be terminated.  I couldn't test this out
since the termination jumpers on the Seagate were very hard to remove.  To
reconfigure the Quantum, I just pulled out its resistor packs.  So the
A3000 SCSI controller was terminated, and the Seagate was terminated,
with the Quantum in between them, unterminated.

	I then connected a 50-pin ribbon cable to the end of the SCSI cable
that the Quantum was connected to.  The original cable was connected to the
Quantum through a connector in the middle of the cable.

	The next step is to mount the Seagate physically within the A3000.
I used the empty floppy disk bracket on the right side of my computer, and
used four screws in the side holes on the bracket to hold the drive.  This
part was slightly tricky since (1) I had to pry the bracket open a little bit
to fit the Seagate's 3.5-inch wide, 1-inch tall body; and (2) I had to move
the Seagate around in the bracket until I found four holes that lined up with
the bracket (the bracket has about 12 holes in it, and the Seagate had 8).
Finally, I connected the power supply --- the A3000 power supply has an
extra connector for a hard drive --- and the SCSI cable, screwed the bracket
into place, and turned the computer on.

	My usual Workbench setup appeared, and I ran HDToolbox to configure
the drive.  It found the Seagate at SCSI ID #5, and queried it for its
configuration (use Define New Drive Type under Change Drive Type to
query the drive).  It did this successfully, and I partitioned the drive
into three chunks:  a 100 MB partition for development tools, a 159 MB
partition for my new Work: volume, and a 259 MB partition for scratch
and ultimately something like Linux or NetBSD.  After this, I formatted
each partition, and ran DiskSpeed 3.4 to test its speed.  The results
were ... mediocre.  The fastest the drive did was about 1.7 MB per
second reading from a file with long-aligned data into Fast RAM.  However,
the write speeds were generally less than 10% slower!  I think this is due
to an onboard 256K cache on the drive that caches writes.  While I was
disappointed at the results, they didn't really mean too much to me.
I had noticed earlier that most of my compiles, TeX processing, and graphics
programs were more CPU-bound than I/O-bound.   Nevertheless, it is about
three times faster than my uncached Quantum.  So while I can't brag about
how fast my drive is, it doesn't affect me much practically.

	Meanwhile living with the drive is pretty much a pleasure.  It's
very quiet, and I have so much space!  One of the first things I did was to
render a long Vista Pro animation to the scratch partition and play it back
on the disk.  Playback was smooth, with a few jumps; but more importantly, I
didn't have to worry about disk space.  I've just migrated my entire Work:
partition over, making the entire Quantum my boot drive.  I do realize now
that I'm going to have to reorganize my work directory since AmigaDOS
doesn't deal too well with too many directories.  And who knows how many
top-level directories I could put in a 159 MB partition?

DOCUMENTATION

	The documentation is a small booklet that tells you how to
set the drive up.  The hardware section is pretty good and to-the-
point, but the software section assumes you're going to use this
drive under MS-DOS, and mentions all sorts of neanderthal concepts
like 32 MB limits and using DEBUG to format a drive.

	The Commodore "Introducing the Commodore Amiga 3000" booklet is
also quite good and clear.  It does have conflicting advice for
terminating devices, but if you just terminate your SCSI wire at
both ends, you should be fine.  This booklet will show you how to
open up your A3000, install memory (the directions here are the best
I've seen) and other things like cards and drives.

LIKES AND DISLIKES

	I like the space.  The speed isn't as fast as I'd hoped it would be,
but I can live with it.  The drive is really small --- it's smaller than my
disk drive.  The drive is also quiet.

	The only thing I didn't like are the configuration jumpers for the
terminators:  they're recessed and quite hard to remove without a pair of
very small pliers.

COMPARISON TO OTHER SIMILAR PRODUCTS

	Two other drives that are in its price range are the Maxtor LX-540S
and the Seagate ST3600N.  Both are much faster and only a little bit more
expensive.  If I had to do it over again, I would get someone to drive me
down to Fry's Electronics (a California chain store for electronic goodies),
and buy the Maxtor drive for $699.  It's just as small, about 4 milliseconds
faster than my drive on the average in access time (according to a Byte
Magazine test), and probably transfers faster, too.  The Seagate 3600N is a
little slower than the Maxtor, but it's also about $50 cheaper and faster
than my drive.

BUGS

	None:  it's completely transparent.

VENDOR SUPPORT

	I haven't tried it, but Seagate does have technical support lines,
FAXes, and a BBS.  They do insist that you go to your dealer first, but they
don't charge for support like Quantum does.

	[UPDATE:  Quantum no longer charges for technical support.
	Thanks to helpful Net reader Joseph P. Hillenburg for this
	update.  - Dan]

WARRANTY

	It's a 2-year warranty.

CONCLUSIONS

	I like the drive, even if it's not the fastest in its class.  Thanks
to good SCSI support on the Amiga side, it was easy to install and have up
running in under 20 minutes.  If you have $150 more money to spend, get the
Maxtor LX-540S, a much faster drive with a little bit more capacity.

COPYRIGHT NOTICE

	Copyright 1993 Andre Yew.  All rights reserved.

---

   Daniel Barrett, Moderator, comp.sys.amiga.reviews
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