On Tue, 21 Aug 2001, Kent Borg wrote:
If I read the quoting correctly (sound familiar?),
Matthew Sell
<msell(a)ontimesupport.com> asked:
As a discussion - what technically makes the
difference between a
mainframe and a mini? Are there physical comparisons to be made or
performance?
It is an ecosystem thing. It's an IBM thing.
A "mainframe" is a computer that, when new, was classed with the
biggest, nastiest, business IBMs available.
It doesn't matter if it weighs a lot or is faster than the mainframes
of an earlier generation, it depends upon its own generation. Also,
the fastest supercomputers of an era are kinda beyond mainframe, and
they lose their "super" qualification as new computers exceed them and
become "former supercomputers". Mainframes tend to stay
mainframes--obsolete maybe, but still mainframes. And frequently are
still in use long after they become obsolete.
I think the distinction between supercomputers and mainframes is even
deeper than that. Supercomputers are designed to do things very very
fast. Mainframes are designed to do many many things at once. The two
goals frequently aren't convergent.
Mainframes tend to put a lot of effort into highspeed
IO, are
expensive, and can do lots of transactions well. (Because expensive
means you want to keep them busy.)
Mainframes are very good at serving thousands, if not hundreds of
thousands of *simultaneous* transactions.
Peace... Sridhar
-kb