🚀 go-pugleaf

In article <8284@gollum.twg.com> david@twg.com (David S. Herron) writes:

>So to compare an Amiga with Unix to a '386 -- The A3000 has a much faster
>bus (20 MByte/sec vs. ~1-3 MByte/sec; unless I get a Tyan machine but that
>runs me $10,000).  

Some of the '386s these days are MCA or EISA based, either of which is in
the same ballpark as the A3000 expansion bus.  You do, in general, pay for
it in those machines too.

>The Amiga also has SCSI-II coming in at somewhere around 1MB/sec - 5 MB/sec 
>(depending on drive); what the speed of ESDI interfaces?  

That's actually SCSI-I running at those speeds.  The SCSI-I limit is around
5MB/sec.  Most drives don't go that fast, and for those that do, they don't
go fast for long.  The extra transfer speed of SCSI can really win for very
high end drives, and for multiple drive systems.  EDSI goes at about 1.5 MB/s,
which is about the speed of the standard asynchronous SCSI transfer.

What's really going to make a difference under UNIX is the multitasking 
performance of your hard disk, which most PClones don't address.  Since the
Amiga OS itself is multitasking, we tend to think in those terms from the
ground up.  The question you ask for determining multitasking hard disk
performance is "how much CPU time is available when the hard disk controller
is running full speed".  For the A3000 and a 1.5 MB/s hard disk going full
speed, you get about 96% of the CPU time for tasks that aren't disk bound.

>Another consideration is hardware reliability.  These 386 clones around
>here simply haven't impressed me with their Solidness and Reliability...

I'm sure the quality of the more established Clone vendors is up there with
that of the Amiga.  I'm equally sure that a good number of the cheaper ones
aren't things I would feel safe investing in.  Its apparently common practice
at the bottom end to violate timing parameters and other specs in the design
to eek out a bit more performance performance, at least in a cool room, for
the same price.  As a computer designer, I get real nervous when I see 
timing specs violated -- that's just plain begging for trouble.

><- David Herron, an MMDF & WIN/MHS guy, <david@twg.com>


-- 
Dave Haynie Commodore-Amiga (Amiga 3000) "The Crew That Never Rests"
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	Standing on the shoulders of giants leaves me cold	-REM