From owner-freebsd-questions Tue Oct 22 17: 7:51 2002 Delivered-To: freebsd-questions@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 3AE8A37B401 for ; Tue, 22 Oct 2002 17:07:49 -0700 (PDT) Received: from maild.telia.com (maild.telia.com [194.22.190.101]) by mx1.FreeBSD.org (Postfix) with ESMTP id A64C743E65 for ; Tue, 22 Oct 2002 17:07:48 -0700 (PDT) (envelope-from erikt@midgard.homeip.net) Received: from d1o913.telia.com (d1o913.telia.com [195.252.44.241]) by maild.telia.com (8.12.5/8.12.5) with ESMTP id g9N07l08014659 for ; Wed, 23 Oct 2002 02:07:47 +0200 (CEST) X-Original-Recipient: Received: from falcon.midgard.homeip.net (h76n3fls20o913.telia.com [213.67.148.76]) by d1o913.telia.com (8.8.8/8.8.8) with SMTP id CAA13831 for ; Wed, 23 Oct 2002 02:07:46 +0200 (CEST) Received: (qmail 73254 invoked by uid 1001); 23 Oct 2002 00:07:43 -0000 Date: Wed, 23 Oct 2002 02:07:42 +0200 From: Erik Trulsson To: "Kevin A. Pieckiel" Cc: freebsd-questions@freebsd.org Subject: Re: Dell server with 6 GB RAM Message-ID: <20021023000742.GA67482@falcon.midgard.homeip.net> Mail-Followup-To: "Kevin A. Pieckiel" , freebsd-questions@freebsd.org References: <20021022233951.GA84639@pacer.dmz.smartrafficenter.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20021022233951.GA84639@pacer.dmz.smartrafficenter.org> User-Agent: Mutt/1.5.1i 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 On Tue, Oct 22, 2002 at 07:39:51PM -0400, Kevin A. Pieckiel wrote: > I'm looking at buying a Dell PowerEdge 2650. These servers can come with > up to 6 GB RAM according to Dell's web site. Now, correct me if I'm wrong, > but what good does that much RAM do when I only have a 32-bit address space? > What am I missing here? How can the hardware or the OS support more than > 4 GB RAM? The latest x86 CPUs (from the Pentium-II onwards) has the capability to physically address a 36-bit address space. This is done by using some extensions to the MMU to map virtual memory to physical in a special way and requires OS support to work. A single process still cannot address more than 4GB at once, but you could have one process using 3GB and another process the other 3GB. Now, the natural question is of course: "Does FreeBSD support more than 4GB RAM?" The answer is no, it does not and there are currently no plans that I know of to add such support in the near future either. -- Erik Trulsson ertr1013@student.uu.se To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message