From owner-freebsd-questions Wed Feb 20 12:56:54 2002 Delivered-To: freebsd-questions@freebsd.org Received: from smtp02.wxs.nl (smtp02.wxs.nl [195.121.6.54]) by hub.freebsd.org (Postfix) with ESMTP id 1595C37B402 for ; Wed, 20 Feb 2002 12:56:49 -0800 (PST) Received: from cybertron.kruijff ([213.10.151.186]) by smtp02.wxs.nl (Netscape Messaging Server 4.15) with ESMTP id GRUNIM00.YDG; Wed, 20 Feb 2002 21:56:46 +0100 Date: Wed, 20 Feb 2002 21:56:46 +0100 From: Alex X-Mailer: The Bat! (v1.53d) Reply-To: Alex X-Priority: 3 (Normal) Message-ID: <14217053982.20020220215646@cybertron.tmfweb.nl> To: =?ISO-8859-1?B?U/hyZW4gTmVpZ2FhcmQ=?= Cc: questions@freebsd.org Subject: OT: Re: Max RAM supported by Hardware In-Reply-To: <1556477954.20020220210026@e-box.dk> References: <1556477954.20020220210026@e-box.dk> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8bit Sender: owner-freebsd-questions@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG Hello Søren, Wednesday, February 20, 2002, 9:00:26 PM, you wrote: SN> Linux can as standard support up to 1GB RAM, if more is present you SN> need to compile the kernel with support for the large amount of RAM. SN> Linux also supports up to 64GB RAM, although 32bit only allows 4GB (as SN> I understand it, I'm not an expert). SN> What about FreeBSD, is it the same here, or how does it work in the SN> worlds best OS? SN> -- SN> Med venlig hilsen/Best regards, SN> Søren Neigaard mailto:neigaard@e-box.dk SN> -- SN> "Any sufficiently advanced bug is indistinguishable from a feature." SN> To Unsubscribe: send mail to majordomo@FreeBSD.org SN> with "unsubscribe freebsd-questions" in the body of the message My anwser if a short off-topic anwser, but you may just like it. Because one first has to look at the underlaying layer we first look at the hardware. A 32 bit adress structer allows for 2^32 = 2 * 1024^3 = 2G adressable memory locations. But there is a trick. We divered the adress in BASE and OFFSET. In the case of Linux (base on what you wrote) the base gets multiply by 32 (2^5). Then the offset is added to it. This is posible because the software-code and data is usaly near to each other, so we don't need to send the BASE alot. Then the software part: Sorry i don't know this. -- Best regards, Alex To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message