Newsgroups: comp.sys.sgi
Path: utzoo!utgpu!jarvis.csri.toronto.edu!dgp.toronto.edu!juancho
From: juancho@dgp.toronto.edu (John Buchanan)
Subject: Re: Experiences with 4D/2xx as timesharing systems?
Message-ID: <8904131149.AA05789@explorer.dgp.toronto.edu>
Organization: University of Toronto, CSRI
References: <89Apr9.160219edt.38129@neat.ai.toronto.edu> <30349@sgi.SGI.COM>
Date: Thu, 13 Apr 89 07:49:14 EDT

In article <30349@sgi.SGI.COM> jmb@patton.SGI.COM (Jim Barton) writes:
>In article <89Apr9.160219edt.38129@neat.ai.toronto.edu>, rayan@ai.toronto.edu (Rayan Zachariassen) writes:

>> During testing on the personal iris, some anomalies showed up that could
>> be explained by the scheduler or VM being tuned for a single-user workstation
>> environment.  For example running a certain (non-graphics) program would
>> cause lost ether packets and horrible response time on the iris, but the
>> same program is apparently wellbehaved on other machines.  Similarly, logging
>> out of the PI causes lost packets.  Anyone experienced similar anomalies
>> on the 4D/2xx?  Anyone using them for timesharing?
>
>Main problem is with the window manager, which is pretty heavyweight.  For all 
>that nice display and all, it takes lots of memory, which has to be fought
>over with the application you are running in a limited memory system.  If
>you really aren't interested in graphics, don't start the window manager,
>and the performance will be very good (you >said< server, right?).  Try
>running your same application on a Sun 4 with NeWS and 8Mb of memory (assuming
>you can get Sun to sell you one) and amuse yourself with the results.

	In the above text rayan forgot to metion that we were not using the
console during much of this testing. (At least the testing that I was
involved in.)  We were trying to run a ray tracing package which is very
floating point intensive.  When I tried to log in it reminded me of the old
days around here when 30-60 of us lived on a vax780.  In short there was no
real time response at all.  This is a cause for concern since it does pertain
to the server aspect of these machines.  

>I thought the net might be interested in the quasi-official SGI answer.
>
>> Thanks,
>> 
>> rayan
>> 
>> AI/NA/Theory, DCS, U of Toronto
>
>My pleasure.
>
>-- Jim Barton
>Silicon Graphics Computer Systems    "UNIX: Live Free Or Die!"
>jmb@sgi.sgi.com, sgi!jmb@decwrl.dec.com, ...{decwrl,sun}!sgi!jmb
>
>  "I used to be disgusted, now I'm just amused."
>			- Elvis Costello, 'Red Shoes'
>--