Experiences with 4D/2xx as timesharing systems?

[jim frost]

>    Aren't there any other companies with multiprocessors?

Sure.  Sequent, Encore, and IBM come to mind immediately.  SGI beats
all of them in price/performance although the Encore is set up for
heavy use, not as a workstation, and performs very well as a large
multiuser machine, making it very competitive in that kind of market.
I hear bad things about Sequent reliability and IBM <-> UNIX still
strikes me as an oxymoron even with AIX and OSF so you can basically
throw them out.

What it comes down to is "what are you looking for".  SGI beats them
all in the workstation and superworkstation market, no questions
asked, competitive even without the geometry engine.  Even though it's
SysV, it's not very SysV and many BSD programs can be built with few
changes.  You can configure a 4D as multiuser but it probably won't
support many.  Encore is not in the workstation market, but instead
has machines which support hundreds of online users in a very
cost-effective manner.  Unfortunately their best market is education
where there isn't always a lot of money to be had.

There are probably other companies which have similar products but I
haven't dealt with them at all.  Apologies if I missed any big ones.

>What about Connection, Convex, and others?
>Those are multiprocessor machines.

I think you can throw out Connection.  It's not a multiprocessor
machine like you're accustomed to and the entire design of the system
is such that it probably won't ever support UNIX (makes for good
reading though -- twelve dimensional architecture).  It's really a
great thing for heavy-duty parallel computation tasks in batch mode,
not interactive or multiuser.

jim frost
madd at bu-it.bu.edu