From owner-freebsd-amd64@FreeBSD.ORG Tue Mar 14 11:38:13 2006 Return-Path: X-Original-To: freebsd-amd64@freebsd.org Delivered-To: freebsd-amd64@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id A9A0416A420 for ; Tue, 14 Mar 2006 11:38:13 +0000 (UTC) (envelope-from kono@kth.se) Received: from omega.nanophys.kth.se (daemon.nanophys.kth.se [130.237.35.96]) by mx1.FreeBSD.org (Postfix) with ESMTP id E368143D53 for ; Tue, 14 Mar 2006 11:38:12 +0000 (GMT) (envelope-from kono@kth.se) Received: from omega.nanophys.kth.se (localhost [127.0.0.1]) by omega.nanophys.kth.se (8.13.4/8.13.1) with ESMTP id k2EBcQDP091567; Tue, 14 Mar 2006 12:38:26 +0100 (CET) (envelope-from kono@kth.se) Received: from localhost (localhost [[UNIX: localhost]]) by omega.nanophys.kth.se (8.13.4/8.13.1/Submit) id k2EBcQkE091566; Tue, 14 Mar 2006 12:38:26 +0100 (CET) (envelope-from kono@kth.se) X-Authentication-Warning: omega.nanophys.kth.se: kono set sender to kono@kth.se using -f From: Alexander Konovalenko Organization: KTH To: JoaoBR Date: Tue, 14 Mar 2006 12:38:25 +0100 User-Agent: KMail/1.9.1 References: <20060313221836.5491916A420@hub.freebsd.org> <200603141106.13693.kono@kth.se> <200603140740.38388.joao@matik.com.br> In-Reply-To: <200603140740.38388.joao@matik.com.br> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200603141238.26235.kono@kth.se> Cc: freebsd-amd64@freebsd.org Subject: Re: amd64 slower than i386 on identical AMD 64 system? X-BeenThere: freebsd-amd64@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list Reply-To: kono@kth.se List-Id: Porting FreeBSD to the AMD64 platform List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 14 Mar 2006 11:38:13 -0000 On Tuesday 14 March 2006 11:40, JoaoBR wrote: > > so where is your comparism? My point was that the same hardware is faster > running i386 > > I experience this also on X2 machines but do not have two machines to > compare I have a X2-4400-SMP running amd64 and a X2-4200-SMP running i386 > and it gives me the same numbers running ubench > I have experienced that -O3 and -ffast-math optimizations flags on AMD64 might cause degrade in performance, meaning that -O2 is the fastest. When you compile your ports what opt. flags do you use? Try to reinstall ubench with different flags. Also code produced with gcc4.x is faster then system compiler and has no degrade effect. Some time ago I was interested in fast scientific computations and did some primitive benchmark tests (http://daemon.nanophys.kth.se/~kono/testfcpu) I just wonder what will happen if you run ubench (compiled for i386) on AMD64, will performance overcome amd64 ubench? /Alexander Konovalenko