Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!csd4.milw.wisc.edu!bionet!apple!apple.com!desnoyer
From: desnoyer@apple.com (Peter Desnoyers)
Newsgroups: comp.protocols.tcp-ip
Subject: Re: MacII FTP speeds on Ethernet
Message-ID: <3258@internal.Apple.COM>
Date: 31 Jul 89 23:44:59 GMT
Sender: usenet@Apple.COM
Organization: Apple Computer, Inc.
Lines: 38
References:<9559@phoenix.Princeton.EDU> <8907250124.AA23044@multimax.encore.com>

In article <8907250124.AA23044@multimax.encore.com> bzs@ENCORE.COM (Barry 
Shein) writes:
> >Can somebody tell me what the bottleneck is on FTP transfer rates for
> >a MacII on ethernet?  I am running two MacII's on a subnet in the 
> >Atmospheric Sciences program here at Princeton, with a Sun 3/280
> >file server also on the net.  I have the Apple ethernet cards in
> >the machines, and am running NCSA Telnet 2.3 (which has server
> >FTP support).  Basically, between the mac and the server I am
> >getting no better than about 35K bytes/sec for binary transfers,
> >no matter how I tweak the protocol parameters.

The numbers I have seen for memory-to-memory MacTCP and AppleTalk 
transaction protocol performance are very close. I would suspect that
the actual hardware driver that receives the packet (and is common
to both stacks) is the bottleneck.

That bottleneck is about an order of magnitude faster than the FTP
performance I see to a Sun (about 35kbyte/s, like Barry).  

> I believe if you run benchmarks writing the disk locally you'll find
> it peaks at around 50K bytes/sec. With the additional overhead of the
> network activity (those disks are all PIO, right?) you're probably
> doing well at those speeds.

My SC80 runs considerably faster than that. (I did a quick-and-dirty
benchmark just now and got ~150kbyte/s to duplicate a file. One-way
performance should be better.) My guess is that the bottleneck is in
NCSA Telnet, or at least in its interface with MacTCP and the file system.
 

                                      Peter Desnoyers
                                      Apple ATG
                                      (408) 974-4469

Disclaimer - I make no claims about the performance or any other 
characteristics of Apple products. These figures are for comment only.
Also, I don't mean to put down the fine efforts of the people who have
produced NCSA Telnet.