SUMMARY: Solaris/SunOS speed

From: Ralph Finch (
Date: Mon Oct 09 1995 - 17:22:25 CDT

Though I'm still not real sure, I'm tentatively concluding that
Solaris is indeed slower than SunOS for interactive use. However if
somebody has additional insight on this I and others would like to
hear it.

The original question:

Is Solaris 2.4 really quite a bit slower than SunOS 4.1.x, as it seems
to me? If not (if the slowness is in our configuration), how can we
speed it up?

To clarify some things: I notice the slowness even without background
jobs running, but it's especially bad when even just one numerical
model is running in the background. Under SunOS 4.1.2, I didn't
notice a bad slowdown until I had 2-3 jobs running in the backround.
The slowness is not a result of running in binary compatibility mode,
we've recompiled everything. Also, our sysadmins say we've installed
patches (see below). The slowness is apparent doing trivial things
like iconizing or opening applications, focus switching, and so on.
It no longer has the fairly snappy feel I was used to, instead reminds
me of the old 4/260 I was using without the graphics accelerator.

Now the responses. I have not summarized them since there didn't seem
to be a clear definitive answer.

From: Yuchou Hu <>

It seems to be between 50-100% slower relative to 4.1.x. A task that
takes 100 sec on 4.1 now takes abetween 150-200 sec.

From: (Edward Almasy)

In my limited experience (only one machine converted to Solaris - all
the rest still using SunOS), Solaris does seem slower, but I don't
think we're seeing a factor of two slowdown.

From: (Marc Gibian)

I don't have a wealth of Solaris 2.4 experience yet, but what I have
seen around me when other groups have upgraded may be relevent. It
would seem that network loading is much "worse" with Solaris 2.4, and
that NIS+ in particular can burn up a lot of bandwidth.

[Note: we are not running NIS+, it's not compatible with our sendmail
I'm told.]

From: Alan Chan <A.Chan@CdnAir.CA>

Make sure you have the latest kernel jumbo patch. 101945-xx We are
using 101945-32 on our machine. Do a "cat /etc/motd" will tell you
which patch you are using. Back in Solaris 2.3, I could believe the
performance gain we had after we installed the latest kernel jumbo
patch. Same may be true for Solaris 2.4.

[Note: our sysadmin says we have installed the above patch, it was
necessary to get openwindows to work. However the motd doesn't
reflect the patch number.]

From: Casper Dik <casper@Holland.Sun.COM>

Just check your paging rate. Solaris 2.x uses somewhat more memory and
this may effect paging. Paging kills interactive performance.

[Note: haven't done formal paging comparisons btwn SunOS and Solaris.
But, the lousy perfomance I'm seeing doesn't seem to be a function of

On the other hand, OW 3.4 uses an interactive scheduling class.
It manipulates the priority of the X process with the input focus
to run at a higher priority.

I have never noticed any slowness in Solaris 2.4, but then I haven't
been running numerical background jobs. I do run compiles and stuff and
that usually doesn't affect performance that much.

If you run OW and have installed kernel patch 101945-32 I owuldn't know
what could be wrong, off hand. If you have installed 101969-05, then
that could be you rproblem. If you run vold, you need to have 101907-05
as well (otherwise it leaks memory).

Are you running OW or R5? And what are you running on the SS2s?

[Note: We are running Openwindows. Another poster (below) says R5
will run faster but you lose answerbook. Most of the time the SS2 is
not running anything in the background, but has GNU Emacs 19.29
windows, Netscape, the usual Sun tools (calendar, mail, perfmeters,)]

Have you looked at your vmstat output? (Especially the "sr" column)

[Note: haven't done this yet.]

From: Chris Royle <>

The answer's "yes" - plain and straight forward. It's because the kernel
overheads in Solaris 2 (partly because of the fact that it's threaded, I
think) are much higher than in SunOS4. Rumour has it, however, that
Solaris 2.5 improves noticeably on this situation. Be thankful you aren't
trying to run Solaris 2.[123] - they were very considerably worse than 2.4!

[Note: can somebody confirm 2.5 performance?]

From: Jas (Matthew K) <>

You will find Solaris seems slower interactively because of latency
problems rather than the fact that it is slower. this is mainly
because of STREAMS. STREAMS has higher latency than mbuf structures
(and the likes) which BSD uses. but on the other hand it has higher
throughput. you also need more memory for a Solaris as compared to a
SunOS box. 32M under SunOS is abotu equiv to 40M on Solaris. part from
that they should behave similarly. you will also find some things will
run faster under Solaris than SunOS (such as nfsd).

From: Damian Murphy <>

OpenWindows 3.4 which shipped as the GUI for Solaris for Solaris 2.4
seems to run noticeably slower than X11R6 when run on the same

NOTE: there are a few things to be aware of if you move to X11R6
i.e. it does use display postscript so Answerbook does not work.

With Solaris 2.x NFS is better, MP works and many packages are
beginning to no longer ship for SunOs 4.x.

[Note: The MP support and beginning of lack of support for SunOS 4.x
are why I want to switch to Solaris...but I'm stalled until I can
promise users something better than the interactive speed I've seen.]

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