Path: utzoo!utgpu!jarvis.csri.toronto.edu!rutgers!tut.cis.ohio-state.edu!gem.mps.ohio-state.edu!ginosko!uunet!intercon!amanda@intercon.uu.net
From: amanda@intercon.uu.net (Amanda Walker)
Newsgroups: comp.protocols.tcp-ip
Subject: Re: MacII FTP speeds on Ethernet
Message-ID: <1302@intercon.UUCP>
Date: 23 Jul 89 17:54:25 GMT
References: <9559@phoenix.Princeton.EDU>
Sender: news@intercon.UUCP
Reply-To: amanda@intercon.uu.net (Amanda Walker)
Organization: InterCon Systems Corporation
Lines: 29

In article <9559@phoenix.Princeton.EDU>, rpbert@phoenix.Princeton.EDU (Raymond
Pierrehumbert) writes:
> Can somebody tell me what the bottleneck is on FTP transfer rates for
> a MacII on ethernet?

There are a number of factors.  The biggest ones are (in no particular order):

 - SCSI Disk speed:  You will get a speed improvement by using a good
   disk cache or transferring to or from a RAMdisk.

 - Ethernet board & driver:  The faster the board (and .ENET driver) can
   move bits around, the better.  The fastest I have seen in action
   personally are the Dove FastNet III and the Asante MacCon II/E.

 - TCP/IP implementation:  The native NCSA TCP/IP kernel runs in what
   would be "user time" under UNIX.  In other words, most of the protocol
   processing happens during the main event loop.  MacTCP, on the other hand,
   does most of its processing at interrupt time, which means among other
   things that ACKs go out immediately, which keeps the other end's idea of
   the RTT low.  Using MacTCP will give you a significant performance
   improvement "right out of the box."

Hope this helps,

--
Amanda Walker
InterCon Systems Corporation
--
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