From owner-freebsd-stable@FreeBSD.ORG Wed Mar 30 23:23:28 2005 Return-Path: Delivered-To: freebsd-stable@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 62BDB16A4CE; Wed, 30 Mar 2005 23:23:28 +0000 (GMT) Received: from pooker.samsco.org (pooker.samsco.org [168.103.85.57]) by mx1.FreeBSD.org (Postfix) with ESMTP id CE33F43D31; Wed, 30 Mar 2005 23:23:27 +0000 (GMT) (envelope-from scottl@samsco.org) Received: from [192.168.254.21] (rat.samsco.home [192.168.254.21]) (authenticated bits=0) by pooker.samsco.org (8.13.1/8.13.1) with ESMTP id j2UNRGfj013042; Wed, 30 Mar 2005 16:27:16 -0700 (MST) (envelope-from scottl@samsco.org) Message-ID: <424B3473.9010108@samsco.org> Date: Wed, 30 Mar 2005 16:21:23 -0700 From: Scott Long User-Agent: Mozilla/5.0 (X11; U; FreeBSD amd64; en-US; rv:1.7.5) Gecko/20050321 X-Accept-Language: en-us, en MIME-Version: 1.0 To: "Greg 'groggy' Lehey" References: <20050330222439.GU84137@wantadilla.lemis.com> <20050330223546.GA4705@troutmask.apl.washington.edu> <20050330224445.GW84137@wantadilla.lemis.com> <424B2FBA.1020102@samsco.org> <20050330231541.GZ84137@wantadilla.lemis.com> In-Reply-To: <20050330231541.GZ84137@wantadilla.lemis.com> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit X-Spam-Status: No, score=-2.8 required=3.8 tests=ALL_TRUSTED autolearn=failed version=3.0.2 X-Spam-Checker-Version: SpamAssassin 3.0.2 (2004-11-16) on pooker.samsco.org cc: FreeBSD Stable Users cc: FreeBSD-amd64@FreeBSD.org cc: Steve Kargl Subject: Re: Problems with AMD64 and 8 GB RAM? X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 30 Mar 2005 23:23:28 -0000 Greg 'groggy' Lehey wrote: > On Wednesday, 30 March 2005 at 16:01:14 -0700, Scott Long wrote: > >>Greg 'groggy' Lehey wrote: >> >>>On Wednesday, 30 March 2005 at 14:35:46 -0800, Steve Kargl wrote: >>> >>> >>>>On Thu, Mar 31, 2005 at 07:54:39AM +0930, Greg 'groggy' Lehey wrote: >>>> >>>> >>>>>None of these problems occur when I use 4 GB memory. About the only >>>>>strangeness, which seems to come from the BIOS, is that it recognizes >>>>>only 3.5 GB. If I put all DIMMS in, it recognizes the full 8 GB >>>>>memory. >>>> >>>>I had 4 bad out of 12 tested where the DIMMs were Crucial PC2700 2GB >>>>Reg. ECC DIMMs. >>> >>>OK, this makes sense. It might also explain why the 4 GB >>>configuration only recognizes 3.5 GB. >> >>No, and I'm going to make this an FAQ and post it in a very obvious >>place, since 4+ GB is so easy to get and people don't seem to understand >>the PC architecture very well. > > > That's not easy to understand when it's barely documented. Thanks for > the info: it helps a lot. > > This may still be a hint, though: that memory hole doesn't show up > during a boot with 8 GB RAM. How come? Is the system trying to map > RAM over the PCI hole? > > It looks as if I should get a verbose boot listing with 8 GB. It'll > be a couple of hours before I find time to reboot this machine. In > the meantime, there's a verbose boot with 4 GB at > http://www.lemis.com/grog/Images/20050331/obelix-dmesg. I'm told it > shows a number of strange things, including incorrect reporting of > on-chip cache sizes. > The SMAP will show the hole. It's well documented in most PC archtitecure books. Scott