From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from pigeon.gentoo.org ([69.77.167.62] helo=lists.gentoo.org) by finch.gentoo.org with esmtp (Exim 4.60) (envelope-from ) id 1JJ4Ht-0002Du-Mf for garchives@archives.gentoo.org; Sun, 27 Jan 2008 09:58:53 +0000 Received: from pigeon.gentoo.org (localhost [127.0.0.1]) by pigeon.gentoo.org (Postfix) with SMTP id 9AA7EE03A4; Sun, 27 Jan 2008 09:58:51 +0000 (UTC) Received: from 0815-web.localdomain (static.21.48.46.78.clients.your-server.de [78.46.48.21]) by pigeon.gentoo.org (Postfix) with ESMTP id 4D61FE03A4 for ; Sun, 27 Jan 2008 09:58:51 +0000 (UTC) Received: by 0815-web.localdomain (Postfix, from userid 1007) id 3CBC59DCBD1; Sun, 27 Jan 2008 10:58:54 +0100 (CET) X-Spam-Checker-Version: SpamAssassin 3.2.1 (2007-05-02) on 0815-web.localdomain X-Spam-Level: X-Spam-Status: No, score=-100.1 required=5.0 tests=AWL,BAYES_00,HTML_MESSAGE, PLING_QUERY,RCVD_IN_PBL,RCVD_IN_SORBS_DUL,RDNS_DYNAMIC,USER_IN_WHITELIST autolearn=no version=3.2.1 Received: from [192.168.1.33] (ip-62-143-21-146.1411O-CUD12K-04.ish.de [62.143.21.146]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by 0815-web.localdomain (Postfix) with ESMTP id 0E5E89DCBD1 for ; Sun, 27 Jan 2008 10:58:52 +0100 (CET) Message-ID: <479C55D6.70406@j-schmitz.net> Date: Sun, 27 Jan 2008 10:58:46 +0100 From: Justin User-Agent: Thunderbird 2.0.0.9 (X11/20071218) Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-Id: Gentoo Linux mail X-BeenThere: gentoo-user@lists.gentoo.org Reply-to: gentoo-user@lists.gentoo.org MIME-Version: 1.0 To: gentoo-user@lists.gentoo.org Subject: [gentoo-user] Speed up with pbzip2 or not!? X-Enigmail-Version: 0.95.5 Content-Type: multipart/alternative; boundary="------------000107030301010309090600" X-Archives-Salt: daed47e2-80f1-452f-a1e5-50c549b43980 X-Archives-Hash: ced22c75a8418ba4be2265a1ce61a742 This is a multi-part message in MIME format. --------------000107030301010309090600 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Hey guys! Yesterday I found this article http://gentoo-wiki.com/HOWTO_Speed_up_decompression_with_pbzip2 and was very happy, because I'm an owner of an Q6600. So I tried to reproduce the benchmark from the wiki article but got that bad results: test # time *bzip2* -d -kf linux-2.6.23.tar.bz2 real 0m11.672s user 0m11.306s sys 0m0.367s test # time *pbzip2* -d -p4 -kf linux-2.6.23.tar.bz2 real 0m25.554s user 0m24.862s sys 0m0.683s So the parallel version took more than the double time! To test whether this is a problem of my Pc I tested this on an Dual Core with the same result. An test with 7z was much better: test # time *7za* x -y linux-2.6.23.tar.bz2 real 0m4.642s user 0m8.379s sys 0m0.327s All tests where done in a tmpfs off 1GB on 2GB RAM. So my questions is what did I do wrong? I also tested it with different CFLAGS, but my CFLAGS are basically very conservative. (-O2 -march=prescott -pipe -fomit-frame-pointer) --------------000107030301010309090600 Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Hey guys!

Yesterday I found this article http://gentoo-wiki.com/HOWTO_Speed_up_decompression_with_pbzip2 and was very happy, because I'm an owner of an Q6600.

So I tried to reproduce the benchmark from the wiki article but got that bad results:

test # time bzip2 -d -kf linux-2.6.23.tar.bz2

real    0m11.672s
user    0m11.306s
sys     0m0.367s


test # time pbzip2 -d -p4 -kf linux-2.6.23.tar.bz2

real    0m25.554s
user    0m24.862s
sys     0m0.683s

So the parallel version took more than the double time!

To test whether this is a problem of my Pc I tested this on an Dual Core with the same result.

An test with 7z was much better:


 test # time 7za x -y linux-2.6.23.tar.bz2

real    0m4.642s
user    0m8.379s
sys     0m0.327s


All tests where done in a tmpfs off 1GB on 2GB RAM.


So my questions is what did I do wrong?

I also tested it with different CFLAGS, but my CFLAGS are basically very conservative. (-O2 -march=prescott -pipe -fomit-frame-pointer)
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