From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 19698 invoked by alias); 12 Apr 2010 12:56:07 -0000 Received: (qmail 19689 invoked by uid 22791); 12 Apr 2010 12:56:06 -0000 X-SWARE-Spam-Status: No, hits=0.8 required=5.0 tests=BAYES_50,FREEMAIL_FROM,RCVD_IN_DNSWL_NONE,T_RP_MATCHES_RCVD,T_TO_NO_BRKTS_FREEMAIL X-Spam-Check-By: sourceware.org Received: from imr-db02.mx.aol.com (HELO imr-db02.mx.aol.com) (205.188.91.96) by sourceware.org (qpsmtpd/0.43rc1) with ESMTP; Mon, 12 Apr 2010 12:56:02 +0000 Received: from mtaout-ma01.r1000.mx.aol.com (mtaout-ma01.r1000.mx.aol.com [172.29.41.1]) by imr-db02.mx.aol.com (8.14.1/8.14.1) with ESMTP id o3CCtMcR017066 for ; Mon, 12 Apr 2010 08:55:57 -0400 Received: from [192.168.1.65] (99-13-231-72.lightspeed.snjsca.sbcglobal.net [99.13.231.72]) by mtaout-ma01.r1000.mx.aol.com (MUA/Third Party Client Interface) with ESMTPA id 0A562E0000BE for ; Mon, 12 Apr 2010 08:55:56 -0400 (EDT) Message-ID: <4BC3185C.8060006@aol.com> Date: Mon, 12 Apr 2010 12:56:00 -0000 From: Tim Prince Reply-To: tprince@computer.org User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9.1.9) Gecko/20100317 Thunderbird/3.0.4 MIME-Version: 1.0 To: gcc-help@gcc.gnu.org Subject: Re: -mtune option for Intel Nehalem References: <854137.56938.qm@web65306.mail.ac2.yahoo.com> In-Reply-To: <854137.56938.qm@web65306.mail.ac2.yahoo.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit x-aol-global-disposition: G X-AOL-SCOLL-SCORE: 0:2:413401248:93952408 X-AOL-SCOLL-URL_COUNT: 0 x-aol-sid: 3039ac1d29014bc3185c5e86 X-AOL-IP: 99.13.231.72 Mailing-List: contact gcc-help-help@gcc.gnu.org; run by ezmlm Precedence: bulk List-Id: List-Archive: List-Post: List-Help: Sender: gcc-help-owner@gcc.gnu.org X-SW-Source: 2010-04/txt/msg00089.txt.bz2 On 4/11/2010 11:02 PM, Rayne wrote: > Hi all, > > I can't seem to find the -mtune option for Intel Nehalem architectures (specifically Intel Xeon X5570). I was recommended -mtune=barcelona, but I got an error when compiling that. The closest is -mtune=nocona, which I believe is for the Core2 chips. > > Are there any mtune options for Intel Nehalem (for any version of GCC)? > > Do you mean you want to use an old version of gcc, issued prior to the advent of -mtune=barcelona? That would reduce your performance potential for vectorized code. It should be obvious, as Nehalem came later than Barcelona, that there would be no optimization for Nehalem in older versions. You would have to experiment yourself to see whether -mtune=nocona helps performance in your case. It's certainly not feasible to give you recommendations covering all old gcc versions, even if we could guess the other factors of your case. -- Tim Prince