From owner-freebsd-amd64@FreeBSD.ORG Mon Sep 27 02:04:45 2004 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 DFE8F16A4CE for ; Mon, 27 Sep 2004 02:04:45 +0000 (GMT) Received: from front2.npgco.com (front2.npgco.com [207.192.213.25]) by mx1.FreeBSD.org (Postfix) with ESMTP id 809D443D49 for ; Mon, 27 Sep 2004 02:04:45 +0000 (GMT) (envelope-from jlfenton@npgcable.com) Received: from [24.121.45.49] ([24.121.45.49]) by front2.npgco.com (8.12.11/8.12.11) with ESMTP id i8R24i7Z017720 for ; Sun, 26 Sep 2004 21:04:44 -0500 Message-ID: <41577570.6020000@npgcable.com> Date: Sun, 26 Sep 2004 19:05:36 -0700 From: Joseph Fenton User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.7.2) Gecko/20040803 X-Accept-Language: en-us, en MIME-Version: 1.0 To: freebsd-amd64@freebsd.org References: <20040924210947.GC6597@iib.unsam.edu.ar> <20040926024730.GA2530@dragon.nuxi.com> <415753BD.2040107@pythonemproject.com> <4157637F.9090009@error404.nls.net> In-Reply-To: <4157637F.9090009@error404.nls.net> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: freebsd i386 on amd64 hardware? 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: Mon, 27 Sep 2004 02:04:46 -0000 Ketrien I. Saihr-Kesenchedra wrote: > > Bearing in mind that I don't work for AMD, my understanding is that > AMD has always planned on three sockets for the Athlon64 - 754 (single > channel), originally because it can be put on a 5-layer PCB. Socket > 940 for Opterons for dual channel, but requiring a 6-layer PCB. And > Socket 939 because that one less pin allows for 5-layer PCBs and dual > channel. The 754 socket (one HT port and single-channel mem) was destined for laptops. The 940 (three HT ports and dual-channel mem) needs the extra layers for proper operation. The 939 keeps the dual-channel, but replaces two of the HT ports with extra power and ground pins. All the extra power and ground pins means less current surge and therefore needs fewer layers. Making it one pin less keeps you from accidentally sticking it in the wrong socket.