From owner-freebsd-amd64@FreeBSD.ORG Sat Jan 1 09:32:22 2005 Return-Path: Delivered-To: freebsd-amd64@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 7FFE216A4CE for ; Sat, 1 Jan 2005 09:32:22 +0000 (GMT) Received: from mailout08.sul.t-online.com (mailout08.sul.t-online.com [194.25.134.20]) by mx1.FreeBSD.org (Postfix) with ESMTP id D53FA43D2D for ; Sat, 1 Jan 2005 09:32:21 +0000 (GMT) (envelope-from mike@reifenberger.com) Received: from fwd05.aul.t-online.de by mailout08.sul.t-online.com with smtp id 1CkfcS-0001H5-00; Sat, 01 Jan 2005 10:32:20 +0100 Received: from fw.reifenberger.com (r3OkeQZdgemHWR-WU3zvoowZ88a66PZyoluBBIHBeiZUdwweG04wZq@[84.128.70.12]) by fmrl05.sul.t-online.com with esmtp id 1CkfcQ-026tHM0; Sat, 1 Jan 2005 10:32:18 +0100 Received: from localhost (mike@localhost)j019WIv3093129 for ; Sat, 1 Jan 2005 10:32:18 +0100 (CET) (envelope-from mike@reifenberger.com) X-Authentication-Warning: fw.reifenberger.com: mike owned process doing -bs Date: Sat, 1 Jan 2005 10:32:18 +0100 (CET) From: Michael Reifenberger To: freebsd-amd64@freebsd.org In-Reply-To: <20041231221347.GA1467@dragon.nuxi.com> Message-ID: <20050101101909.D93061@fw.reifenberger.com> References: <20041230090557.I82461@fw.reifenberger.com> <20041231221347.GA1467@dragon.nuxi.com> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed X-ID: r3OkeQZdgemHWR-WU3zvoowZ88a66PZyoluBBIHBeiZUdwweG04wZq@t-dialin.net X-TOI-MSGID: 4bfe9dbf-515b-4d5c-a8d3-4734b8f94123 Subject: Re: Migrating i386 to amd64 X-BeenThere: freebsd-amd64@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: Porting FreeBSD to the AMD64 platform List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 01 Jan 2005 09:32:22 -0000 On Fri, 31 Dec 2004, David O'Brien wrote: ... >> BTW: Do I have any benefit of using this hardware (2GB RAM) with amd64 >> in favour of i386 (besides a bigger virtual address space)? > > Yes. A 64-bit kernel is often more efficient because so many of the > kernel data structures these days are 64-bit counters, etc.. Also the > AMD64 ABI has 8 more general purpose registers, which gives the compiler > a lot more to work with in optimizing and allows parameters to be passed > thru registers vs. the slower memory stack. I also would not dismiss the > benefits of the larger virtual address space. There are applications > where the kernel really benefits from not being constrained to its > limited amount of VA in 32-bit mode. > That sounds reasonable. Thanks! Bye/2 --- Michael Reifenberger, Business Development Manager SAP-Basis, Plaut Consulting Comp: Michael.Reifenberger@plaut.de | Priv: Michael@Reifenberger.com http://www.plaut.de | http://www.Reifenberger.com