Memory impact on performance of Sun3

[Roy Smith]

In article <4975 at brl-smoke.ARPA> obrien%pluto at RAND-UNIX.arpa writes:
>  We find that a "normal" Suntools environment, for us, (consisting of
> about 6 or 7 windows) causes the 3/75 to page madly just running the Sun
> utilities, let alone any substantial application code. [...] I would not
> recommend less than 8 Meg for any workstation.

[and in a follow-up article, he clams the same is true for a 3/50, since
4 Meg is all you can ever put on that machine]

	We've got 12 3/50's here and I havn't seen the memory thrashing
described above.  My .suntools sets up 3 perfmeters (local, and keeping an
eye on our 2 file servers), a clocktool (w/ second hand), an rlogin to our
vax, a console, a mailtool, and 3 shelltools (2 iconic).  Typically I've
got an emacs running in one window with some sort of big troff or make in
another.  With the clock and perfmeters waking up every second or two, that
keeps the machine pretty busy.  I don't notice any wild paging going on,
and almost never any swapping.

	I suppose it all depends on what kind of jobs you're running.  Add
to that mix some horrible lisp thing and a 1k x 1k matrix multiply and I
would imagine you'll see some vm activity pretty fast.

	When we started negotiating the purchase of our systems, the 3/50
hadn't been announced yet and we were looking at the 3/75.  Since we had
been running as many as a dozen users on our 4 Meg vax without problems, I
couldn't believe you would want 4 Meg in a personal workstation and decided
to save some money by buying the 3/75-2 (i.e. 2 Meg).  (To this day, some
part of me is still living in the days when we ran 24 users on a 96k 11/45
with a 20k v6 kernel; now we run 1 Meg 4.2 kernels.)

	I was rather annoyed when our salesman tried very hard to talk us
out of it, and surprised (and even more annoyed) when he claimed that they
didn't even make the 3/75-2's in their catalog.  Talking further with some
high-level technical people at Sun convinced me they were right.  "So, if
you won't sell me a 2 Meg system, why do you have them in your catalog at
all?", I asked.  The answer basicly turned out that in order to meet
bidding requirements on certain sales, they needed to be able to present a
system with a lower price tag than the 3/75-4.

	It was around that time that I was getting fed up with Sun (I don't
think the Sequent people realize just how close they came to making a sale
then) but the announcement of the 3/50 sold me.  Now we have our 4 Meg
systems, and we're happy.  And I *still* think 2 Meg would have been
plenty!  1/2 :-)
-- 
Roy Smith, {allegra,philabs}!phri!roy
System Administrator, Public Health Research Institute
455 First Avenue, New York, NY 10016