CMS

[Jim Frost]

In article <1988Aug12.061040.18720 at utzoo.uucp> henry at utzoo.uucp (Henry Spencer) writes:
|In article <19709 at tut.cis.ohio-state.edu> mudd-j at pike.cis.ohio-state.edu (John R. Mudd) writes:
|>... I *liked* VM/CMS from a user point-of-view.  The shop I worked at had a
|>IBM 3090 running VM/XA with 200+ users, and that system was FAST.  Not like
|>some of the delays I've had on some of these Unix-boxes.  Of course, they're
|>not as big as a 3090...
|
|Damn right they aren't.  Unix on a big Amdahl really blasts along too.
|Don't confuse hardware with software; of course a really big mainframe
|is faster than an overgrown mini.

Another thing that people miss is that the 3090 architecture is
designed to offload almost all of the I/O work to other processors.
You send off a command and then forget about it until it's through.
Some of the commands are very complex.  I've seen some UNIX boxes that
do this, too, and they get MUCH better throughput than otherwise.  The
reasons for this are obvious to even the beginner.  Of course the kind
of architecture the 3090 has is going to cost more since you have lots
of periferal processors, but you get high throughput and that's what
people pay for.  It's too bad that no one seems to be using this idea
on UNIX boxes using cheap periferal processors.  Considering some of
the hardware I've seen lately, though, it is probably coming.

Another thing to consider is the available tools.  It's very easy to
get a lot of work done on a UNIX machine -- even if the UNIX machine
can't blast along -- because it has a LOT of stuff running on it.  If
a single user can get his work done in 10 minutes using tools
available under UNIX and can get it done in 40 minutes under something
else without similar tools, you get a much larger user turnover in the
same amount of time.  This has proved to be the case in my experience
with a proprietary OS on the 3090 here (VM/VPS) versus smaller UNIX
boxes.  Students get the same work done faster.  Even though 300
students can't use the hardware at the same time, they don't have to
wait so long to use it; it evens out.

jim frost
madd at bu-it.bu.edu