From chemistry-request@ccl.net Tue May 10 05:41:58 2005 Received: from mailer.gwdg.de (mailer.gwdg.de [134.76.10.26]) by server.ccl.net (8.13.1/8.13.1) with ESMTP id j4A9fslq006398 for ; Tue, 10 May 2005 05:41:55 -0400 Received: from pcboehme.gwdg.de ([134.76.5.4]) by mailer.gwdg.de with esmtpsa (TLSv1:RC4-MD5:128) (Exim 4.42) id 1DVRFR-0001OM-1d; Tue, 10 May 2005 11:41:53 +0200 Message-ID: <428081DA.8040501 * gwdg.de> Date: Tue, 10 May 2005 11:41:46 +0200 From: Christian Boehme User-Agent: Mozilla Thunderbird 1.0 (X11/20041206) X-Accept-Language: de-DE, de, en-us, en MIME-Version: 1.0 To: Luigi Cavallo CC: chemistry * ccl.net Subject: Re: CCL:Opteron or Nocona ? References: In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 8bit X-Virus-Scanned: (clean) by exiscan+sophie X-AUTH-Id: cboehme1 X-Spam-Status: No, score=0.0 required=5.0 tests=none autolearn=failed version=3.0.3 X-Spam-Checker-Version: SpamAssassin 3.0.3 (2005-04-27) on server.ccl.net Dear Luigi, Luigi Cavallo schrieb: > we are going to invest some money for a few computers, and we have to > make a decision between the AMD-Opterons and the Intel-Nocona. What's > better ? We are experienced with the Opterons, but we have no idea about > the Noconas... > > Major codes to run on them will be classical QM packages as ADF, G03, TM, > some AIMD as CPMD, and possibly some classical MD as gromacs. We recently purchased a 32 dual-processor Opteron (2GHz) cluster. We used CPMD and several artificial benchmarks on Opteron and Xeon (3GHz) machines to come to this decision. With CPMD we found that the advantage of the Opteron over the Xeon was very significant for 32-bit memory intensive applications running on both processors of a dual processor box (Intel compiler on both architectures). When using just one processor, the Xeon scored much better. As Intel has not changed the memory interface of the Nocona, I do not think this trend would be different for 64-bit applications. Regarding Fortran compilers, from our experience both the Intel and the Portland can now be used to make production quality 64-bit binaries for the Opterons. Best wishes Christian -- Dr. Christian Boehme GWDG Private: Am Fassberg Wilhelm-Raabe-Str. 15 37077 Gvttingen 37083 Gvttingen email: Christian.Boehme * gwdg.de ChristianBoehme * web.de phone: +49 (0)551 201-1839 +49 (0)551 3077000 fax: +49 (0)551 201-2150 +49 (0)551 3077077