[comp.windows.x] Running X on a Sun 3/50

bernhold@red8.qtp.ufl.edu (David E. Bernholdt) (05/02/91)

We're experimenting with running X on our diskless 4MB Sun 3/50
workstations with 68881 coprocessors.  Using the standard X11R4
distribution, we obtain performance which is, on balance, not too much
worse than with SunView.

It seems logical to suppose that given the configurability of X, there
might be some things to squeeze out a little extra performance on this
platform.  (Please don't respond with "get more memory" or "upgrade to
SS2s" since we're looking specifically at the _existing_ hardware.)

Since the biggest bottleneck seems to be paging over the network, our
first thought is to look for ways to reduce the memory load of the X
system.  On this track, would it be possible and helpful to produce a
special version of Xsun which only supports the 3/50's monochrome
frame buffer?

Any other ideas for improvements over the standard distribution would
also be welcome.  Thanks in advance.
-- 
David Bernholdt			bernhold@qtp.ufl.edu
Quantum Theory Project		bernhold@ufpine.bitnet
University of Florida
Gainesville, FL  32611		904/392 6365

stripes@eng.umd.edu (Joshua Osborne) (05/20/91)

In article <28363@uflorida.cis.ufl.EDU> bernhold@red8.qtp.ufl.edu (David E. Bernholdt) writes:
>We're experimenting with running X on our diskless 4MB Sun 3/50
>workstations with 68881 coprocessors.  Using the standard X11R4
>distribution, we obtain performance which is, on balance, not too much
>worse than with SunView.

Configure a Kernel with no SunView support for the 3/50s, and while you
are doing that remove support for everything else you can.  Making your
kernel smaller will improve your memmory usage more then any wacking on the
server could.

Alternitly there is a package floating around that will turn your 3/50 into
an X terminal (by running a minimal kernel, no daemons (other then a 
crippled init, and X).

>It seems logical to suppose that given the configurability of X, there
>might be some things to squeeze out a little extra performance on this
>platform.  (Please don't respond with "get more memory" or "upgrade to
>SS2s" since we're looking specifically at the _existing_ hardware.)

If you make the 3/50's Xterminals you will need to supply CPU form somewhere.
For our users 8 to a SS1+ has worked Ok.  (the SS1+'s have 28M RAM each
'tho).

>Since the biggest bottleneck seems to be paging over the network, our
>first thought is to look for ways to reduce the memory load of the X
>system.  On this track, would it be possible and helpful to produce a
>special version of Xsun which only supports the 3/50's monochrome
>frame buffer?

Yes.  There was also a posting long ago that speed-up the drawing speed of
text by about 20% for bw2's only.  I'll look for my copy, does anyone
else have one?

>Any other ideas for improvements over the standard distribution would
>also be welcome.  Thanks in advance.

If you insist on using the 3/50's as workstations run vmstat, put a set -v
in your .xinitrc, run vmstat 1.  Use that to see where to put sleeps.  As
a rule of thumb you want one every 2 or 3 programs.  The one after you
start your wm (which you want to start first to prevent things from redrawing).
The current delays for 3/50 are 11secs for normal programs and 24 for twm.
This reduced start-up time on a 3/50 from over 10min to one and a half.

You may want to try telling the server not to do backing store, but leave
save unders on.
-- 
           stripes@eng.umd.edu          "Security for Unix is like
      Josh_Osborne@Real_World,The          Multitasking for MS-DOS"
      "The dyslexic porgramer"                  - Kevin Lockwood
"CNN is the only nuclear capable news network..."
    - lbruck@eng.umd.edu (Lewis Bruck)