Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!wuarchive!texbell!texsun!newstop!sun!amdahl!dgcad!gary
From: gary@dgcad.SV.DG.COM (Gary Bridgewater)
Newsgroups: comp.os.aos
Subject: Re: AOS/VS -> DG/UX transition
Message-ID: <1156@svx.SV.DG.COM>
Date: 6 Oct 89 08:41:44 GMT
References: <8758@discus.technion.ac.il>
Reply-To: gary@svx.SV.DG.COM ()
Organization: Data General SDD, Sunnyvale, CA
Lines: 50

In article <8758@discus.technion.ac.il> blue%techunix.bitnet@jade.berkeley.edu (Baruch Cochavy) writes:
>        We are now in the process of looking into running DG/UX on our
>old MV/4000 and MV/2000. Can anyone comment on that, or supply some
>performance comparisons, preferably based upon practical experience
>of such an upgrade ?

Yes. DG/UX is a simpler operating system than AOS/VS. Since the iron is the
same, executing fewer instructions makes DG/UX run 'faster'. Since the OS does
less for you you have to do more for it. This is completely analogous to
AOS vs RDOS and is why people who were happy with RDOS were unhappy with
AOS. DG/UX is more complicated that RDOS.
Example: DG/UX does highest priority, first-come first-served scheduling vs
AOS/VS's round robin, hueristic scheduling. This makes for quicker scheduling
decisions under DG/UX and is what Unix users want but it may come as a surprise
to people running multiple cpu-bound jobs who are used to AOS/VS. On the other
hand, DG/UX has nothing to compare with Batch - you have to roll your own.
But, in general, AOS/VS and Unix are both minicomputer oriented, multi-
user operating systems. They both want to provide the same sorts of services
and they generally expect the user to be logged onto a terminal.
Its hard to go much beyond that since you provide no indication of what
you are currently using the systems for and/or what you plan to do with them
under DG/UX. But if you just want Unix then you will get it. Be sure to get
4.02. MV DG/UX is a meld of primarily Sys V 5.3 with BSD 4.2 extensions (
streams, job control, Berkeley 4.2 TCP/IP). The MV C compiler and the
linker are 99% the same as AOS/VS. You can move .obs back and forth to
some extent (this may change, but it is handy while converting).
Of course this excludes anything that is OS specific like sys_xxx calls.
DG/UX should not be confused with MV/UX in any way.

>        Also, and I realize this is not the best news group to handle
>it, can someone comment on the AViiON, or compare it to VAX11/780 or
>something else in the same range ?

Running DG/UX 4.10 using the GNU compiler, its seems to be on a par with our
Sun 4/280. My AViiON 310 has a 189MB shoebox disk while the Sun 4 has 2 900MB
Fuji disks so I lose a lot in terms of swapping, file I/O, etc. I get it back
in quicker CPU cycles. In terms of our MV systems - it kicks an MV/20000
in the teeth. I don't have a local 40000 to compare to. An MV/20000 is
about twice an MV/10000sx and an MV/10000sx is about 1.5 a VAX 11/780.
(An MV/10000sx is about 2.5x an MV/4000 .)
Running X, I can paint the screen in about the time a Sun 3/60 takes to
clear the screen and define the window borders. These aren't hard numbers
but then this isn't comp.arch and I'm not Bob Cousins. :->
AV DG/UX 4.10 is a meld of SysV 5.3+4 and BSD 4.3 with a twist of POSIX and
88K OPEN.

I speak as a user only and these are my own observations.
-- 
Gary Bridgewater, Data General Corp., Sunnyvale Ca.
gary@sv4.ceo.sv.dg.com or 
{amdahl,aeras,amdcad,mas1,matra3}!dgcad.SV.DG.COM!gary
No good deed goes unpunished.