Article View: comp.sys.ibm.pc.misc
Article #10204Buying a Multi-user Computer System with a Unix Operating System
From: Dwight Joe
Date: Thu, 31 Dec 1992 04:04
Date: Thu, 31 Dec 1992 04:04
192 lines
10661 bytes
10661 bytes
I thought perhaps that you people might find the following to be interesting.
I wrote it as a final report in one my classes. Please note that it was
intended to be neither (1) scholarly nor (2) exhaustive but that its purpose
was to provide some reference points for future purchases of computer hardware.
(I did pass the class.)
If you have an opinion, then please send e-mail. Thanks. Enjoy!
(You are free to reference this in any of _your_ reports, provided
that you make a reference to me.)
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(c) 1992,1993
Buying a Multi-user Computer System
with a Unix Operating System
by Dwight Joe
I. Introduction
In purchasing a multi-user computer system, we must
consider the components that form the total system; they include
the operating system, the interconnecting network, the mass-
storage system, the printer, and the personal computer or
workstation. Our focus in this report is the Unix operating
system, off-the-shelf cards and devices for interconnecting the
network and for providing mass storage, a laser printer, and the
80x86 workstations (where I refer only to 80x86 machines with "x
> 2"). Although 80x86-based computers are commonly known as
personal computers, later generations of such machines using the
80386 or 80486 offer the same speed and memory addressability as
traditional workstations; the 80386 and its successors are full
32-bit microprocessors. Furthermore, compared to more
traditional workstations, machines based on the 80486 tend to be
much cheaper and enable financially strapped institutions like
universities to increase the computing resources per student to
an extent beyond what the university could afford for
traditional high-priced workstations.
II. Operating System
Unlike traditional workstations, 80x86 workstations
predominantly run the Microsoft Disk Operating System (MS-DOS),
and few run any variant of Unix. Nevertheless, many companies
produce a Unix OS for 80x86 machines; examples are Next, SCO,
SunSoft, and Univel (USL in collaboration with Novell). With
the exception of USL's Unix, SVR4.2, each variant of Unix
produced by these companies are incompatible with most other
major Unix OS's on the market.
So, which Unix OS should we select? The decision rests on
two important criteria: (1) compatibility with other Unix OS's
to ensure that our selected Unix OS can run many future Unix
applications in the event that it does not become the de facto
industry standard and (2) relatively low cost. One important
but less significant criterion is the incorporation of the X-
Window System, which is widely used in the engineering
community.
Among Unix implementations, SVR4.2 (which is sold as
UnixWare by Novell) best meets these criteria. It is compatible
with seven major Unix OS's; among these are SunOS/Solaris,
SVR3.2, BSD, and Xenix. The X-Window System is included, and so
is TCP/IP networking in the base version of SVR4.2. The base
version supports only the vital functions expected in a Unix
implementation; in this way, the size and cost are reduced. The
base version requires only a minimum configuration of 4 MB of
memory and a 60-MB hard drive and is expected to cost in the
range of $100-$150.[1]
III. Interconnecting Network
The Unix OS provides networking capability that requires
communication boards and cable to link the 80x86 workstations
into a network. For our purposes, we assume a network of 8
computers among which we wish to share data and programs.
So, what type of network should be select? The most
important criteria are that the selected network can be serviced
at many repair sites and that the amortized cost per workstation
be relatively low. The presence of many repair companies
fosters competition in terms of price and speed of service.
When data is shared among many users across many computers, we
must try to minimize the down time of a network in order to
avoid the ire of the users, so the speed of service is
important. If one repair site proves unreliable, we can easily
switch to another repair site simply because there are many
repair sites due to the popularity of the selected network.
In terms of popularity, the best local area network is
Ethernet. The typical price of an Ethernet set, including
communication cards and cables for an 8-computer network plus a
fileserver, should be approximately $2800; the amortized cost
per workstation (including the fileserver) is about $300
dollars, which is relatively inexpensive compared to the cost of
the workstation itself. The price is virtually invariant with
respect to the type of 80x86 computer that we choose to buy
because almost all IBM-PC compatible machines are 100%
compatible with IBM, and hence, a card that plugs into one PC
clone can also be plugged into another PC clone. Also, because
of the intense competition in the PC clone market and the
related peripherals market, the prices of all PC hardware is
continuously declining at least for the immediate future[2].
IV. Storage
To service the mass-storage needs of the 8 computers on our
network, we need at least 1 file server. We can choose from a
number of different fileservers: AcerFrame 1000, ALR PowerPro,
AST Premium SE 4/50, Compaq Systempro/Lt, DECpc 450ST, Dell
450SE/2, Everex Step 486DX2/50 EISA Tower, Gateway 50-MHz 486DX2
EISA, IBM PS/2 Model 95 XP 486, NCR 3447, Northgate 486 EISA
DX2, Tangent MultiServer, etc.
Which fileserver should we select? The two most important
criteria are (1) relatively low cost and (2) saturation
behavior. The prices of the fileservers can range from about
$5000 to $20,000. With regards to the second criterion, network
saturation occurs as a result of file access requests that
become bottlenecked at the fileserver. Network saturation is
important because once a network reaches saturation, the
throughput per workstation decreases as the number of
workstations added to the network increases.
Fortunately, for our 8-computer network, none of the above
fileservers reach saturation in benchmarks performed by the
staff at Byte. It recommends Compaq Systempro/LT and NCR 3447
as the overall best fileservers running Unix; also, the Tangent
MuiltiServer is recommended for those on a tighter budget.
Since our chosen Unix OS is SVR4.2 and since only the NCR 3447
runs that implementation, we choose the NCR 3447. The NCR
fileserver costs about $11,000, which puts it in the middle of
the field. For that price, we get 1.34 Gbytes of storage, and
an additional 10 hard drives, each having 0.67 Gbyte of storage,
can be added.[3]
A relatively inexpensive tape-backup system is also needed
in our network. Such a system can be obtained for a relatively
inexpensive price of $299.95.[2]
V. Printer
Of course, we also wish to print the data and other results
produced by our multi-user computer system. For about $1500, we
can attach a high-quality laser printer to the network.[2]
VI. Workstations
Finally, the core of our computer network is the computing
nodes: 80x86 workstations. Due to intense price competition in
the PC market, the 80x86 machines have been virtually turned
into commodity products with profit margins that are razor thin.
The result is that we can buy a 80486 workstation for about
$3500. Most of the IBM-PC's and clones are reliable and cost
effective.
Further, there are few differences among them. The main
criterion in selecting one brand over another is the long term
prospects of the company selling the machine. Buying one from a
company that collapses before the warranty has expired might
leave us with very expensive repair bills in the event that the
workstation breaks down.
One good machine is the Compaq Deskpro 4/33i with a 33-Mhz
80486. This workstation is comparable in speed to a
Sparcstation 1+ but costs only about $3500; the Sparcstation
costs at least $5000.[4]
VII. Conclusion
Therefore, our selected multi-user computer system has the
following costs:
1 Unix OS = $150
network equipment = $2800
1 fileserver = $11,000
8 workstations @ $3500 = $28,000
1 laser printer = $1500
Thus, the total cost is approximately $43,450 for a cluster of 8
Compaq Deskpro 4/33i workstations connected via Ethernet, a NCR
3447 fileserver, a laser-printer, an Ethernet network, and USL's
SVR4.2 Unix OS. For an even higher performance system, we can
substitute Compaq Deskpro 50M workstations for the Compaq
Deskpro 4/33i workstations. The former is comparable in speed to
a Sparcstation 2 but costs about $7000; a Sparcstation 2 costs
about $20,000.[5] So the total cost of the system with Compaq
Deskpro 50M workstations becomes $71,450.
References
[1] Yager, Tom and Ben Smith. "Is Unix Dead?" Byte. September,
1992. Pages 134-146.
[2] Radio Shack catalogue for 1993, Pages 155-164.
[3] Platt, Stephen, Tadesse Giorgis, Leslie Reisz, and Steve
Apiki. "Fast 486 File Servers" Byte. October 1992. Pages 212-
220.
[4] Eglowstein, Howard and Stan Wszola. "486 Systems for a
Graphical World" Byte. November 1992. Pages 209-236.
[5] Smith, Ben and Raymond Ga Cote. "Stalking the Ultimate
Workstation" Byte. November 1992. Pages 192-108.
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Jinsei no imi wa nan desu ka. Sister, can you | \| |`
Shitte itara oshiete kuremasen ka. spare a coin? | | -+-
| /| / \
Copyright 1992, 1993 Disclaimer: 1 + 1 = 3 |
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Newsgroups: comp.sys.ibm.pc.misc,comp.sys.sun.misc Path: arc1-ca.pugleaf.net!sparky!uunet!stanford.edu!nntp.Stanford.EDU!underdog From: underdog@leland.Stanford.EDU (Dwight Joe) Subject: Buying a Multi-user Computer System with a Unix Operating System Message-ID: <1992Dec31.040449.11817@leland.Stanford.EDU> Sender: ?@leland.Stanford.EDU Organization: Miners for a Heart of Gold References: <BzzHKw.Fyv@news.udel.edu> Date: Thu, 31 Dec 92 04:04:49 GMT Lines: 192