From owner-freebsd-stable Wed Jul 18 9:23:27 2001 Delivered-To: freebsd-stable@freebsd.org Received: from mail2.uniserve.com (mail2.uniserve.com [204.244.156.10]) by hub.freebsd.org (Postfix) with ESMTP id 3BC0337B403 for ; Wed, 18 Jul 2001 09:23:23 -0700 (PDT) (envelope-from tom@uniserve.com) Received: from mail2.uniserve.com ([204.244.156.10]) by mail2.uniserve.com with esmtp (Exim 3.13 #1) id 15Mu6Y-000MWP-00; Wed, 18 Jul 2001 09:23:18 -0700 Date: Wed, 18 Jul 2001 09:23:18 -0700 (PDT) From: Tom X-Sender: tom@athena.uniserve.ca To: Jonathan Belson Cc: Erik Trulsson , freebsd-stable@FreeBSD.ORG Subject: RE: FreeBSD 4.3 and 6G RAM In-Reply-To: Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-freebsd-stable@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG On Wed, 18 Jul 2001, Jonathan Belson wrote: > > > i have an intel 4400 platform equipped with 4 xeon processors and 6G ram. > > > the mainboard is based on the ServerWorks ServerSet II HE chipset (by > > > intel), which supports up to 16G RAM (or 32G, i'm not sure at the moment). > > > > > > i have installed FreeBSD 4.3-STABLE. > > > > > > unfortunately, the system seems unable to work with this amount of ram. > > > > FreeBSD does not support more than 4G RAM (at least not on x86, I > > don't know about Alpha). > > My suggestion would be to remove the extra 2G RAM from the machine and > > see if things work better then. (FreeBSD will not be able to use it > > anyway so you don't lose anything by removing it.) > > Dumb question: by my calculations, a 32bit address register can only > address 2**32 bytes of memory, ie. 4GB. Is it possible for your > average P3/Athlon to addres more than this? Does it use banking/ > MMU tricks? > A Xeon processor can address more than 4GB. Considering it is an Intel process, I imagine they use segment registers to do this. The original 8088/8086 was a 16bit processor but had a 20bit address space. You used segment registers to choose blocks of memory you could access. I believe the Xeon is the only x86 processor that can address more than 4GB. Tom To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-stable" in the body of the message