From owner-freebsd-questions@FreeBSD.ORG Thu Apr 9 13:11:08 2015 Return-Path: Delivered-To: freebsd-questions@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [8.8.178.115]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id 6DF09A16 for ; Thu, 9 Apr 2015 13:11:08 +0000 (UTC) Received: from bede.qeng-ho.org (bede.qeng-ho.org [217.155.128.241]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id 0AA6C691 for ; Thu, 9 Apr 2015 13:11:07 +0000 (UTC) Received: from arthur.home.qeng-ho.org (arthur.home.qeng-ho.org [172.23.1.2]) by bede.home.qeng-ho.org (8.14.9/8.14.7) with ESMTP id t39DAxPA004764; Thu, 9 Apr 2015 14:10:59 +0100 (BST) (envelope-from freebsd@qeng-ho.org) Message-ID: <55267A63.4040503@qeng-ho.org> Date: Thu, 09 Apr 2015 14:10:59 +0100 From: Arthur Chance User-Agent: Mozilla/5.0 (X11; FreeBSD amd64; rv:31.0) Gecko/20100101 Thunderbird/31.6.0 MIME-Version: 1.0 To: =?UTF-8?B?UGllcnJlLVl2ZXMgUMOpbmVhdQ==?= , freebsd-questions@freebsd.org Subject: Re: How FreeBSD manage more than 4GB on 32 bits architecture References: <5526408F.1090005@asim.lip6.fr> <20150409114941.692910293a8120de4dafd400@yahoo.es> <20150409114906.6dd4379c@archlinux> <55264DC5.9070606@asim.lip6.fr> In-Reply-To: <55264DC5.9070606@asim.lip6.fr> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.18-1 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 09 Apr 2015 13:11:08 -0000 On 09/04/2015 11:00, Pierre-Yves Péneau wrote: > > On 04/09/2015 11:49 AM, Ralf Mardorf wrote: >> On Thu, 9 Apr 2015 11:49:41 +0200, Eduardo Morras wrote: >>> You are looking for PAE. >> >> Hi, >> >> PAE does not support up to 8TB as the OP mentions. PAE is limited >> to 64 GiB. >> >> > > Sorry, I forgot something important. My physical memory is 1TB, and as > Ralf said, PAE is limited to 64GB (36 bits). I'm looking for a 40 bits > support (at least). I've just realised the original post said > According to the architecture handbook(*), "FreeBSD could > theoretically handle memory configurations up to 8TB on a 32 bit > platform." Having followed the link, I find that's a partial quote, and the full one was "In fact, if the mmu were capable of it, FreeBSD could theoretically handle memory configurations up to 8TB on a 32 bit platform. However, since most 32 bit platforms are only capable of mapping 4GB of ram, this is a moot point." I.e. it was talking about the software architecture of the kernel virtual memory manager on 32 bit processors, not the hardware. -- Those who do not learn from computing history are doomed to GOTO 1