From owner-freebsd-stable@FreeBSD.ORG Thu Apr 6 14:38:26 2006 Return-Path: X-Original-To: freebsd-stable@freebsd.org Delivered-To: freebsd-stable@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id BEB6516A420 for ; Thu, 6 Apr 2006 14:38:26 +0000 (UTC) (envelope-from petefrench@ticketswitch.com) Received: from mail.ticketswitch.com (mail.ticketswitch.com [194.200.93.188]) by mx1.FreeBSD.org (Postfix) with ESMTP id 5B5D543D5C for ; Thu, 6 Apr 2006 14:38:25 +0000 (GMT) (envelope-from petefrench@ticketswitch.com) Received: from [172.16.1.6] (helo=dilbert.firstcallgroup.co.uk) by mail.ticketswitch.com with esmtp (Exim 4.52 (FreeBSD)) id 1FRVcq-000Ev6-EH; Thu, 06 Apr 2006 15:38:20 +0100 Received: from petefrench by dilbert.firstcallgroup.co.uk with local (Exim 4.60 (FreeBSD)) (envelope-from ) id 1FRVcq-0004pJ-4c; Thu, 06 Apr 2006 15:38:20 +0100 To: nikolas.britton@gmail.com, vivek@khera.org In-Reply-To: Message-Id: From: Pete French Date: Thu, 06 Apr 2006 15:38:20 +0100 Cc: freebsd-stable@freebsd.org Subject: Re: Pros and Cons of amd64 (versus i386). X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 06 Apr 2006 14:38:26 -0000 > If your running a desktop, I'd recommend sticking with 32-bit. For a > server doing a lot of I/O, go with 64-bit. The Athlon will run very > fast in both modes, but your software compatibility is better in i386 > mode. Interesting comment - I have a server at home with a pair of Opteron 242s in it that I just built and was wondering about switching to amd64 mode. It's primary purpose is to provide file servring over Samba, mail using imapd (large mbox format files) and also to be a firewall using PF/ALTQ. So it's pretty much entirely doing I/O. I was thinking of moving this to amd64, but was kind of put off by results from a test system I setup using an Athlon 64 3700+ to talk to this machine. The opteron box is currently running 6.1-PRE/i386, and the 3700 is runiing either Windows XP or 61-PRE/amd64. Under Windows I can completely saturate the ether comming in, and get 70% bandwidth going out (it's gig ether). Under amd64 on the client end I can only get about 55% utilisation in both directions. This surprised me a lot as when I was running i386 on that box it was always faster. Of course a number of variables have changed since then (primarily moving from a broadcom gigabit card to using the onboard realtek card), but I was concened that the difference was due to the 64 bit operating system, as opposed to superior windws drivers, which seemed unlikely! I know that what I should do is install i386 on the client and test again, but doing that will lose my only 64 bit environment so I am loathe to do so. Any comments ? -pcf.