From owner-freebsd-questions@FreeBSD.ORG Wed Apr 15 16:52:54 2009 Return-Path: Delivered-To: freebsd-questions@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id A77D7106566B for ; Wed, 15 Apr 2009 16:52:54 +0000 (UTC) (envelope-from utisoft@googlemail.com) Received: from mail-ew0-f171.google.com (mail-ew0-f171.google.com [209.85.219.171]) by mx1.freebsd.org (Postfix) with ESMTP id 031B08FC15 for ; Wed, 15 Apr 2009 16:52:53 +0000 (UTC) (envelope-from utisoft@googlemail.com) Received: by ewy19 with SMTP id 19so3191262ewy.43 for ; Wed, 15 Apr 2009 09:52:53 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=googlemail.com; s=gamma; h=domainkey-signature:mime-version:received:reply-to:in-reply-to :references:from:date:message-id:subject:to:cc:content-type :content-transfer-encoding; bh=Fw3btJ6QWMdXzgN9U/6aLdSdAIzY4KA4RYMRV5udyc8=; b=Ri7Qc4Pa5wLNI2h0bHC7JObMowtTnPTngWT6CJiG/FpxrfC+C6TXJDWBr4XdpGGYjD wThTc6TaOraihe7M82nAlpIDwW5C/SjrDSYruPJAClawVoRIw+EZ1SqiXuSLAvst2ObO 9Nkods5VtC/rfoDp1ehM56gDQ0RnyptOJLcjc= DomainKey-Signature: a=rsa-sha1; c=nofws; d=googlemail.com; s=gamma; h=mime-version:reply-to:in-reply-to:references:from:date:message-id :subject:to:cc:content-type:content-transfer-encoding; b=SkQ1MEUkq0AGBMW7aDd67cwwOJUF5hLaAoGPd6lWeMuD2r6xbBRyF2hK+Fc5UHfG9z iK1vEE37YoZG+OG6BCgzIQ3Lw8ug8cfT43HscYa1Lq3Puzb/THXrFkXyB3x7CIlpfr7d 5wjCxAnG0VEaAQjGZYDOrsvUAXiQNFzdANojM= MIME-Version: 1.0 Received: by 10.210.37.11 with SMTP id k11mr2004348ebk.29.1239814373096; Wed, 15 Apr 2009 09:52:53 -0700 (PDT) In-Reply-To: <20090415140841.37ad038b@gluon.draftnet> References: <20090415140841.37ad038b@gluon.draftnet> From: Chris Rees Date: Wed, 15 Apr 2009 17:52:38 +0100 Message-ID: To: Bruce Cran Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: Alexander Best , freebsd-questions@freebsd.org Subject: Re: hard drive performance X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list Reply-To: utisoft@gmail.com List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 15 Apr 2009 16:52:55 -0000 2009/4/15 Bruce Cran : > On Wed, 15 Apr 2009 13:54:13 +0200 (CEST) > Alexander Best wrote: > >> hi there, >> >> i have 2 hard drives running. the first one is SATA300 and the other >> one UDMA100. here are the dmesg entries: >> >> ad0: 238474MB at ata0-master SATA300 >> ad1: 157066MB at ata4-master >> UDMA100 >> >> i've tried to test the drives' performances using the following >> commands: >> >> dd if=/dev/ad0 of=/dev/null bs=1m count=300 >> and >> dd if=/dev/ad1 of=/dev/null bs=1m count=300 >> >> the results are: >> ad0 = 314572800 bytes transferred in 4.325645 secs (72722751 >> bytes/sec) ad1 = 314572800 bytes transferred in 5.166126 secs >> (60891430 bytes/sec) >> >> the results for ad0 are a bit disappointing though. is this normal or >> is bs=1m wrong? > > 70MB/s is a very good transfer rate for a hard drive. The 300MB/s rate > refers to the maximum the physical interface can support, but drives > never get close to that because they can't read from disk at that > speed. > > -- > Bruce Cran Hehe, I think everyone makes that mistake when they're enthusiastic and sometimes even somewhat experienced. It's always such a disappointment when they realise, I remember when I did too. Chris -- A: Because it messes up the order in which people normally read text. Q: Why is top-posting such a bad thing? A: Top-posting. Q: What is the most annoying thing in e-mail?