From owner-freebsd-stable@FreeBSD.ORG Thu Dec 2 21:59:39 2004 Return-Path: Delivered-To: freebsd-stable@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 0ADA916A4CE for ; Thu, 2 Dec 2004 21:59:39 +0000 (GMT) Received: from smtp3.server.rpi.edu (smtp3.server.rpi.edu [128.113.2.3]) by mx1.FreeBSD.org (Postfix) with ESMTP id 2585343D1D for ; Thu, 2 Dec 2004 21:59:38 +0000 (GMT) (envelope-from drosih@rpi.edu) Received: from [128.113.24.47] (gilead.netel.rpi.edu [128.113.24.47]) by smtp3.server.rpi.edu (8.13.0/8.13.0) with ESMTP id iB2Lxbj5020218; Thu, 2 Dec 2004 16:59:37 -0500 Mime-Version: 1.0 Message-Id: In-Reply-To: <41A2C5C0.3080908@yahoo.com> References: <41A2C5C0.3080908@yahoo.com> Date: Thu, 2 Dec 2004 16:59:36 -0500 To: Rob , freebsd-stable@freebsd.org From: Garance A Drosihn Content-Type: text/plain; charset="us-ascii" ; format="flowed" X-CanItPRO-Stream: default X-RPI-SA-Score: undef - spam-scanning disabled X-Scanned-By: CanIt (www . canit . ca) Subject: Re: make -j$n buildworld : use of -j investigated X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 02 Dec 2004 21:59:39 -0000 At 2:08 PM +0900 11/23/04, Rob wrote: >Hi, > >I have tested following with FreeBSD 5.3-Stable. > >On several different PCs I have used > make -j$n buildworld >with $n ranging from 1 to 9. > >Although people suggest "-j4" as optimal in general >case, I have come to a very different conclusion... So, I finally got around to doing some timings on my newest PC. It is a AMD Athlon(tm) XP 3000+ (2166.43-MHz 686-class CPU) with 1-gig of memory, and fast SATA disks. It was certainly different that what I saw on my previous single-CPU systems. Roughly: Real User Sys Max-LA 2670.86 2071.66 543.49 1.25 buildworld 2751.60 2085.95 603.69 1.35 -j1 buildworld 2825.87 2137.19 637.15 5.58 -j2 buildworld 2887.03 2158.60 648.37 11.85 -j3 buildworld 2856.75 2156.48 647.43 19.06 -j4 buildworld 2851.71 2154.39 647.19 25.43 -j5 buildworld 2850.92 2155.40 646.19 31.59 -j6 buildworld 2850.07 2153.77 648.41 36.19 -j7 buildworld 2852.64 2155.74 647.82 47.00 -j8 buildworld 2851.66 2153.43 650.23 53.51 -j9 buildworld (I've actually done multiple runs of each, but they all show about the same numbers). I had a separate session doing 'uptime's every 30 seconds, and the "Max-LA" column is the maximum load-average that was seen by that separate session. Apparently the faster disks made a much bigger difference than I had expected to see. -- Garance Alistair Drosehn = gad@gilead.netel.rpi.edu Senior Systems Programmer or gad@freebsd.org Rensselaer Polytechnic Institute or drosih@rpi.edu