Path: utzoo!attcan!uunet!unisoft!hoptoad!tim
From: tim@hoptoad.uucp (Tim Maroney)
Newsgroups: comp.protocols.appletalk
Subject: Re: What is EtherTalk speed?
Message-ID: <6047@hoptoad.uucp>
Date: 12 Dec 88 20:41:03 GMT
References: <488@dbase.UUCP> <731@lts.UUCP>
Reply-To: tim@hoptoad.UUCP (Tim Maroney)
Organization: Eclectic Software, San Francisco
Lines: 24

A non-dedicated 8MHz 68000 cannot keep up with an Ethernet, period.
The Mac Ethernet cards use heavy buffering on board.  Aside from this
problem, every network protocol has a certain scheduling latency.  With
Mac TOPS, which uses a proprietary synchronous scheduling mechanism,
this latency is acceptable for LocalTalk or whatever they're calling
AppleBus these days, but becomes rather noticeable on a higher-speed
LAN.  It would be nice if this could be reduced, but it would require a
major rewrite of Mac TOPS.  Even then, my guesstimate is that the
maximum factor of improvement that the Mac could support would be about
six, as opposed to the three times improvement you get now on
Ethernet.  Things might be better on the SEx (the 68030 SE scheduled
for the first half of 1989).

And let's not even talk about FlashTalk; benchmarks done at TOPS showed
that the speedup was far less than three times, and under some
conditions things actually ran slower.  Don't believe everything you
read in ads and in the lapdog trade press.
-- 
Tim Maroney, Consultant, Eclectic Software, sun!hoptoad!tim
"Gangsters would kidnap my math teacher, Miss Albertine, and I'd track them
 down and kill them one by one until she was free, and then she'd break off
 her engagement with my sarcastic English teacher, Mr. Richardson, because
 she'd fallen hopelessly in love with her grim-faced and silent
 fourteen-year-old savior." -- Nite Owl, in WATCHMEN by Alan Moore