From owner-freebsd-current Wed Mar 5 7:33:57 2003 Delivered-To: freebsd-current@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 1B20237B401 for ; Wed, 5 Mar 2003 07:33:56 -0800 (PST) Received: from duke.cs.duke.edu (duke.cs.duke.edu [152.3.140.1]) by mx1.FreeBSD.org (Postfix) with ESMTP id 43A4F43FBF for ; Wed, 5 Mar 2003 07:33:51 -0800 (PST) (envelope-from gallatin@cs.duke.edu) Received: from grasshopper.cs.duke.edu (grasshopper.cs.duke.edu [152.3.145.30]) by duke.cs.duke.edu (8.12.8/8.12.8) with ESMTP id h25FXoG1017926 (version=TLSv1/SSLv3 cipher=EDH-RSA-DES-CBC3-SHA bits=168 verify=NO); Wed, 5 Mar 2003 10:33:50 -0500 (EST) Received: (from gallatin@localhost) by grasshopper.cs.duke.edu (8.11.6/8.9.1) id h25FXj874816; Wed, 5 Mar 2003 10:33:45 -0500 (EST) (envelope-from gallatin@cs.duke.edu) From: Andrew Gallatin MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Message-ID: <15974.6361.471584.917266@grasshopper.cs.duke.edu> Date: Wed, 5 Mar 2003 10:33:45 -0500 (EST) To: David Leimbach Cc: Christopher Fowler , freebsd-current@freebsd.org Subject: Re: IP over IEEE1394? In-Reply-To: <43A441A1-4F17-11D7-A732-0003937E39E0@mac.com> References: <1046874658.5666.27.camel@cfowler.outpostsentinel.com> <43A441A1-4F17-11D7-A732-0003937E39E0@mac.com> X-Mailer: VM 6.75 under 21.1 (patch 12) "Channel Islands" XEmacs Lucid Sender: owner-freebsd-current@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG David Leimbach writes: > True... I guess I didn't state my case clearly enough that I think IP > over firewire > is in itself a good thing for clusters. From my experience with the Apple IP over Firewire, it seems slow, and very high overhead. A dual 800MHz G4 host which can transmit at well over 1 Gb/sec (using ethernet-over-Myrinet) maxes its CPU out at 200Mb/sec, or less with IP over Firewire. (I'd report GigE numbers, but I don't have a GigE switch or a decent enough cable to get a host-host link at 1Gb/s). Its possible that the Apple code just sucked, I don't know. It used a 1500 byte mtu, for example. I'd have thought you'd be able to have much large mtus w/firewire. If the Apple code is typical, then I think that unless you've got some sort of alternate zero-copy protocol running over raw firewire, you'd be better off running GigE, or even multiple 100Mb links. Drew To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message