Altos 5000

[Ti Kan]

In article <1990Aug22.171700.23382 at ico.isc.com> rcd at ico.isc.com (Dick Dunn) writes:
>ti at altos86.Altos.COM (Ti Kan) responds to a flame-ette from Foulk about the
>> with a "standard" SCO driver can support such a requirement?...
>
>This is nonsense.  "Supporting" a user is very much more than allowing a
>terminal to be plugged in.  Quite simply put, it doesn't matter whether you
>can handle the I/O connections or even the I/O bandwidth; you don't have
>the CPU power to support 200 people actually *using* the system.

Believe it or not, we have actually tested our System 5000 running 200
users (mixed applications, consisting of Informix database, Uniplex
word processor, and various others) via our automated MTS (Multi-user
test suite) with really 200 serial connections.  While the performance
with such a load wasn't exactly speedy, it was possible to connect 200
users to it, and is to some extent quite usable.  Obviously, this
requires gobs of memory (the current shipping version of the System
5000 supports 64MB maximum), and fast disks systems (not just disk or
controller hardware, but highly tuned disk device drivers which we
have).

We know that more CPU power is necessary for a large system, thus
new systems with more CPU power, more memory, and more disk
performance is in the works, including multi-processor systems.

The point is that we have anticipated a need for high performance I/O
subsystems in a large UNIX implementation, and this requires not only
speedy hardware, but highly-tuned software designed to squeeze every
bit of performance out of them.  You are *not* going to get that with
any "generic" 386 UNIX products (SCO, Interactive, et. al.) which were
designed to run on some "generic" PC hardware.  Moreover, companies
like SCO and Interactive can't possibly provide the kind of software
reliability that we could, given that we has so finely-tuned our
software specifically for our hardware platform.  In addition to
performance tuning, We exhaustively test our software on our hardware
platform, and fixed many, many bugs that exists on other 386 UNIX
implementations.  A vanilla SCO UNIX release and an XYZ PC combination
would never pass our strict QA standards.

The fact that SCO UNIX-compatible device drivers and application
can drop-in shrink wrapped, and other PC-class expansion boards
can plug-n-play in an Altos 5000 is simply bonus that you don't
get with proprietary hardware/software vendors like Sun, Pyramid,
DEC, etc.

>Disk striping is truly useful, but disk mirroring is mostly a pawn in the
>feature game.  It takes substantially more I/O bandwidth to do the double
>output, and it doubles the cost of disk storage.  Why not spend only a few
>bucks extra and buy reliable disks?

What do you mean by reliable disks?  Any hardware can fail, no matter
how well built it is.  While tape backups are essential, disk mirroring
allows the system to *stay up* in the event one of the mirrored drives
fail.  This is fault-resiliency that many installations are willing
to pay for.  I realize that disk mirroring is expensive, but for
certain applications it is worth it.

Again, the original point of the discussion was the question why
one would choose a box like the Altos 5000 with standard EISA bus
and 486 CPU, but with special expansion I/O cards and special UNIX
release, over a generic PC with SCO or Interactive UNIX.  I think
I have made my argument pretty clear.

-Ti
-- 
Ti Kan                                                                  \\\
vorsprung durch technik!                                                 \\\
Internet: ti at altos.com                                                /// \\\
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