From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from lists.gentoo.org ([140.105.134.102] helo=robin.gentoo.org) by nuthatch.gentoo.org with esmtp (Exim 4.43) id 1EFiEc-0000ei-KP for garchives@archives.gentoo.org; Thu, 15 Sep 2005 01:08:19 +0000 Received: from robin.gentoo.org (localhost [127.0.0.1]) by robin.gentoo.org (8.13.4/8.13.4) with SMTP id j8F12WsZ017301; Thu, 15 Sep 2005 01:02:32 GMT Received: from mail26.sea5.speakeasy.net (mail26.sea5.speakeasy.net [69.17.117.28]) by robin.gentoo.org (8.13.4/8.13.4) with ESMTP id j8F0wnTh011393 for ; Thu, 15 Sep 2005 00:58:51 GMT Received: (qmail 28969 invoked from network); 15 Sep 2005 01:03:38 -0000 Received: from dsl027-182-150.sfo1.dsl.speakeasy.net (HELO chi.speakeasy.net) (rmsand@[216.27.182.150]) (envelope-sender ) by mail26.sea5.speakeasy.net (qmail-ldap-1.03) with SMTP for ; 15 Sep 2005 01:03:38 -0000 Date: Wed, 14 Sep 2005 18:03:38 -0700 From: Bob Sanders To: gentoo-user@lists.gentoo.org Subject: Re: [gentoo-user] hardware advice for dual-processor set-up on gentoo Message-ID: <20050914180338.23d5d59e@chi.speakeasy.net> In-Reply-To: References: <20050912200733.3da4cc99@chi.speakeasy.net> X-Mailer: Sylpheed-Claws 1.0.5 (GTK+ 1.2.10; x86_64-pc-linux-gnu) Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-Id: Gentoo Linux mail X-BeenThere: gentoo-user@gentoo.org Reply-to: gentoo-user@lists.gentoo.org Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Archives-Salt: 6b17030c-9e8c-4708-8bd1-7a64ee5d52f2 X-Archives-Hash: 4981361e2a313a65c5bf3085469e4186 On Mon, 12 Sep 2005 23:47:11 -0500 Denis wrote: > I guess the other advantage is that a good dual Xeon system with 4GB > RAM will run me around $3000, whereas a dual Opteron (with dual core) > system with 4GB RAM will run me more like $4300. If the Opterons are > currently at their memory bandwidth limit, I will have spent the $4300 > for nothing, especially since I need the fastest memory integration I > can get for my codes. > > Would I be better buying a dual Xeon system if I needed to buy right > now instead of waiting for the bandwidth issue to be resolved? > Careful with the dual Xeon - Intel has numerous chipsets. Some better than the other. Unless you spend hours studying the difference, you may end with much older tech for your money. Also, you might be better off now with a 2P Opteron, single core, than an Intel setup. It's less expensive. And, as you're crunching a lot of numbers, the Opteron's faster throughput in the FPU may offset and bandwidth limitation. Only you can tell if your app is more cpu/fpu bound or more memory bound. You might want to emerge - app-admin/sysstat, and characterize your app's system usage and use that to decide which arch features are important to you. Another thing to consider - Intel shares the memory/FSB. Each Opteron has access to a full 6.4 GB/s memory bandwidth, as long as the data set remains with that cpu. Should the data set or data have to come from a non-local memory bank, there will be a delay. So even with a slower memory bus, the Opteron could be faster overall. It depends on what resources your app uses. Bob - -- gentoo-user@gentoo.org mailing list