Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!tut.cis.ohio-state.edu!cs.utexas.edu!uunet!mcvax!kth!draken!ragge
From: ragge@nada.kth.se (Ragnar Sundblad)
Newsgroups: comp.protocols.appletalk
Subject: Re: Ethernet vs LocalTalk
Message-ID: <947@draken.nada.kth.se>
Date: 3 May 89 12:59:32 GMT
References: <29980@apple.Apple.COM> <278@suna.CMI.COM> <24837@ames.arc.nasa.gov>
Reply-To: ragge@nada.kth.se (Ragnar Sundblad)
Organization: Royal Institute of Technology, Stockholm, Sweden
Lines: 38

In article <24837@ames.arc.nasa.gov> medin@cincsac.arc.nasa.gov (Milo S. Medin) writes:
>Wait a sec.  Van got those figures running on a real OS (BSD Unix)
>on properly designed hardware (SUN 3 + Lance chip).  There is *NO
>WAY* you are going to come close with the lousy ethernet controllers
>you get on the MAC-II, and I doubt the Nu-bus can properly
>deal with the transfer rate.  One thing that Van has definitely
>shown is that CPU is not the real problem, it's braindead I/O
>devices!  If you expect real performance, use a real computer.

I have had absolutely *NO PROBLEMS* coming up into this speed - and
higher of course - using my macII with apples/3coms, ok - braindead,
but not at all slow, ethernet controller via the nubus. There is no
DMA, thats a drawback, but on the other hand, I might not be able to
wait for other dma tasks to finish before it can do mine. That's one
reason wy I sometimes prefer "doing it without dma".  The nubus can
under certain circumstances keep up with a speed of 40Mbyte/sec, if
you're using the block transfer facility which just a few devices
support, but normally ~15Mbytes/sec is no problem at all. 10Mbits/sec
(ethernet) is nothing.  What Van really did was patching a completely
I/O- and realtime-braindead os to use one of its i/o-devices at
8-9Mbits/sec. That's really tricky, and any improvement of
unix's-whatsoever is really welcome. Maybe, one day, I can use it for
other things than just the simplest computer applications and
reading/writing news and mail with. :-)

I like unix for some things, sun make resonable machines, but there is
nothing special about any of them. I prefer ruling my own computer,
not having an "os" in between me and the machine. Especially, I don't
like an os taking a lot of cpu time from me. Then unix really isn't a hit.

Apples macII often is a ok compromise, for example for the ethernet
tests I made. There is absolutely *NO WAY* that your sun3 with UNIX
would keep the same speed as my macII have on this task. Maybe a Sun4,
but probably not. A "clean" sun3/4 of course could do the same, but I
don't very much like programming the whole computer.

So please, don't tell me about your sun. I get as impressed or
interrested as if you would tell me about your telephone.