From owner-freebsd-hardware@FreeBSD.ORG Wed Sep 26 16:06:25 2007 Return-Path: Delivered-To: freebsd-hardware@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id D7C6916A417 for ; Wed, 26 Sep 2007 16:06:25 +0000 (UTC) (envelope-from jhb@freebsd.org) Received: from elvis.mu.org (elvis.mu.org [192.203.228.196]) by mx1.freebsd.org (Postfix) with ESMTP id E0CDC13C4A3 for ; Wed, 26 Sep 2007 16:06:25 +0000 (UTC) (envelope-from jhb@freebsd.org) Received: from zion.baldwin.cx (66-23-211-162.clients.speedfactory.net [66.23.211.162]) by elvis.mu.org (Postfix) with ESMTP id 4981F1A3C1A; Wed, 26 Sep 2007 08:48:13 -0700 (PDT) From: John Baldwin To: freebsd-hardware@freebsd.org, jgrosch@juniper.net Date: Wed, 26 Sep 2007 10:09:01 -0400 User-Agent: KMail/1.9.7 References: <20070829174236.6c33ccfc@n2.lands.raad> <20070829205110.GA68658@juniper.net> In-Reply-To: <20070829205110.GA68658@juniper.net> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200709261009.01555.jhb@freebsd.org> Cc: err Subject: Re: 8GB RAM: PAE or not PAE? X-BeenThere: freebsd-hardware@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: General discussion of FreeBSD hardware List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 26 Sep 2007 16:06:26 -0000 On Wednesday 29 August 2007 04:51:10 pm Josef Grosch wrote: > On Wed, Aug 29, 2007 at 05:42:36PM +0200, err wrote: > > Hi > > > > I have an HP DL380 quad core with 8GB of RAM and SAS disks in RAID, with freebsd 6 STABLE on it. > > > > Everything works fine, except for the RAM addressing problem: freebsd sees only 4GB. > > I know it have been discussed, but it could be a problem to me for running a 64bit compiled system; what is the stability of a kernel compiled with the PAE option? > > > > I've a kernel with no modules, and before trying PAE I would know for other people experiences... > > In particular I'm interested in the behavior of ciss, bce, em and usb stuff, and application like Perl, Ruby, PHP 5, MySQL server, heavy MAWK and bzip2 load. > > > > Also, if I boot a PAE kernel, in order to have all my RAM available, I have to set the hw.physmem variable to 8G ? > > > > Thanks > > -- > > Emmanuel Richiardone > > > Based on my experience with PAE I would say, don't. I found PAE to be very > brittle. Not all the drivers work well with PAE. Most recent Intel > processors understand 64bit. I have several machines in our datacenter > which are Intel 5160 running amd64. 4.x + PAE is rather questionable, but 6.x + PAE is quite stable. -- John Baldwin