From owner-freebsd-hackers Tue Mar 5 15:40:16 2002 Delivered-To: freebsd-hackers@freebsd.org Received: from rwcrmhc53.attbi.com (rwcrmhc53.attbi.com [204.127.198.39]) by hub.freebsd.org (Postfix) with ESMTP id 702D837B405 for ; Tue, 5 Mar 2002 15:40:08 -0800 (PST) Received: from InterJet.elischer.org ([12.232.206.8]) by rwcrmhc53.attbi.com (InterMail vM.4.01.03.27 201-229-121-127-20010626) with ESMTP id <20020305234008.XUQV2951.rwcrmhc53.attbi.com@InterJet.elischer.org>; Tue, 5 Mar 2002 23:40:08 +0000 Received: from localhost (localhost.elischer.org [127.0.0.1]) by InterJet.elischer.org (8.9.1a/8.9.1) with ESMTP id PAA33117; Tue, 5 Mar 2002 15:30:00 -0800 (PST) Date: Tue, 5 Mar 2002 15:29:59 -0800 (PST) From: Julian Elischer To: Lars Eggert Cc: Zhihui Zhang , "Rogier R. Mulhuijzen" , freebsd-hackers@FreeBSD.ORG Subject: Re: A weird disk behaviour In-Reply-To: <3C85542B.5060100@isi.edu> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG On Tue, 5 Mar 2002, Lars Eggert wrote: > Zhihui Zhang wrote: > > Several times slower! The point is that writing less data performs > > worse. So I call it weird. > > Huh? You originally said: > > > (1) Write each block fully and sequentially, ie. 8192 bytes. > > > > (2) I still write these blocks sequentially, but for each block I only > > write part of it. > ... > > I find out the the performance of (2) is several times better than the > > performance of (1). Can anyone explain to me why this is the case? > > If (2) is better than (1), then writing *less* data is faster. Which is > it, now? > Um yeah that is what all my suggestions were based on.. > Lars > To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message