From owner-freebsd-stable@FreeBSD.ORG Mon Apr 12 04:37:40 2010 Return-Path: Delivered-To: freebsd-stable@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 3D52D106566C for ; Mon, 12 Apr 2010 04:37:40 +0000 (UTC) (envelope-from maho.nakata@gmail.com) Received: from mail-gx0-f211.google.com (mail-gx0-f211.google.com [209.85.217.211]) by mx1.freebsd.org (Postfix) with ESMTP id EC0298FC17 for ; Mon, 12 Apr 2010 04:37:39 +0000 (UTC) Received: by gxk3 with SMTP id 3so2607858gxk.13 for ; Sun, 11 Apr 2010 21:37:39 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:received:received:sender:date:message-id:to :subject:from:x-mailer:mime-version:content-type :content-transfer-encoding; bh=XNu7hRX66/Rlt+9U/5O8SYNjWo7yfkBkUJkY43s7AMA=; b=YDItiP/D+K4eZc/9S29mRFm/YIds3erpzCnkIvAwWUAW6pjh6isMxINeJC+PAwPP+l 5V8Q7REz7uXvdSl0jWU5pGZNBF+h/cpzUvgCeHQs6+XHqEMigvCFyAR1UDwdi/7IruIB gTwJoka51KiABHZSF4TQz4Ie+/RxN/UvgIfz0= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=sender:date:message-id:to:subject:from:x-mailer:mime-version :content-type:content-transfer-encoding; b=JJhegFoGfWvhWm3yIAGxCX5q092zigt1vO6216SAFxjgP9jwcLj/2xeBV9sZ6a2N3N D4BKs/aR2q1q+/4wOTNuqfjsiDDyq+6U6L8WbH1gT13WzMk3fY0klPSgz1ZU0qysy6BL M+ohcbcNG5dqP/Zvxvt9F5aKYzeduJVZ3IBBc= Received: by 10.101.137.22 with SMTP id p22mr5486838ann.247.1271045540767; Sun, 11 Apr 2010 21:12:20 -0700 (PDT) Received: from localhost (rikad42.riken.jp [134.160.214.42]) by mx.google.com with ESMTPS id 20sm984088yxe.5.2010.04.11.21.12.18 (version=SSLv3 cipher=RC4-MD5); Sun, 11 Apr 2010 21:12:20 -0700 (PDT) Sender: Maho NAKATA Date: Mon, 12 Apr 2010 13:12:13 +0900 (JST) Message-Id: <20100412.131213.4959786962516027.chat95@mac.com> To: freebsd-stable@freebsd.org From: Maho NAKATA X-Mailer: Mew version 6.3 on Emacs 23.1 / Mule 6.0 (HANACHIRUSATO) Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Subject: Only 70% of theoretical peak performance on FreeBSD 8/amd64, Corei7 920 X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 12 Apr 2010 04:37:40 -0000 Hi FreeBSD developers, [the original article in Japanese can be found at http://blog.goo.ne.jp/nakatamaho/e/b5f6fbc3cc6e1ac4947463eb1ca4eb0a ] *Abstract* I compared the peak performance of FreeBSD 8.0/amd64 and Ubuntu 9.10 amd64 using dgemm (a linear algebra routine, matrix-matrix multiplication). I obtained only 70% of theoretical peak performance on FreeBSD 8/amd64 and almost 95% on Ubuntu 9.10 /amd64. I'm really disappointed. *Introduction* I'm a friend of Gotoh Kazushige, the principal developers of GotoBLAS. He told me that FreeBSD is not suitable OS for scientific computing or high performance computing. He says (in Japanese and my translation): > I guess FreeBSD does page coloring, but I don't think FreeBSD considers very large cache > size which recent CPU has. Support of a very large cache on Linux is still not very will > sophisticated, but on *BSDs, its worst; they uses too fine memory allocation method, > so we cannot expect large continuous physical memory allocation. > Moreover, process scheduling is not so nice as *BSD employs an algorithm that > changes physical CPUs in turn instead of allocating one core for such kind of jobs. > Take your own benchmark, and you'll see.. *Result* Machine: Core i7 920 (42.56-44.8Gflops) / DDR3 1066 OS: FreeBSD 8.0/amd64 and Ubuntu 9.10 GotoBLAS2: 1.13 dgemm result OS : FLOPS : percent in peak FreeBSD : 32.0 GFlops : 71% Ubuntu : 42.0-42.7GFlops : 93.8%-95.3% Thanks, -- Nakata Maho http://accc.riken.jp/maho/ , http://ja.openoffice.org/ Nakata Maho's PGP public keys: http://accc.riken.jp/maho/maho.pgp.txt