From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from pigeon.gentoo.org ([208.92.234.80] helo=lists.gentoo.org) by finch.gentoo.org with esmtp (Exim 4.60) (envelope-from ) id 1P1LZ9-0005Ut-F0 for garchives@archives.gentoo.org; Thu, 30 Sep 2010 16:01:03 +0000 Received: from pigeon.gentoo.org (localhost [127.0.0.1]) by pigeon.gentoo.org (Postfix) with SMTP id D4111E079B; Thu, 30 Sep 2010 16:00:20 +0000 (UTC) Received: from mail.ukfsn.org (mail.ukfsn.org [77.75.108.10]) by pigeon.gentoo.org (Postfix) with ESMTP id A9AD0E079B for ; Thu, 30 Sep 2010 16:00:20 +0000 (UTC) Received: from localhost (smtp-filter.ukfsn.org [192.168.54.205]) by mail.ukfsn.org (Postfix) with ESMTP id A8F1BDEB6D for ; Thu, 30 Sep 2010 17:00:19 +0100 (BST) Received: from mail.ukfsn.org ([192.168.54.25]) by localhost (smtp-filter.ukfsn.org [192.168.54.205]) (amavisd-new, port 10024) with ESMTP id ZVe6V3nnr8xC for ; Thu, 30 Sep 2010 17:00:19 +0100 (BST) Received: from humphrey.ukfsn.org (unknown [78.32.181.186]) by mail.ukfsn.org (Postfix) with ESMTP id 5B147DEC4B for ; Thu, 30 Sep 2010 17:00:19 +0100 (BST) From: Peter Humphrey Organization: at home To: gentoo-user@lists.gentoo.org Subject: Re: [gentoo-user] Normal disk speed? Date: Thu, 30 Sep 2010 17:00:16 +0100 User-Agent: KMail/1.13.5 (Linux/2.6.35-gentoo-r9; KDE/4.5.1; x86_64; ; ) References: <201009301510.43043.lists@f_philipp.fastmail.net> In-Reply-To: <201009301510.43043.lists@f_philipp.fastmail.net> 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 Content-Type: Text/Plain; charset="iso-8859-15" Content-Transfer-Encoding: 7bit Message-Id: <201009301700.17007.peter@humphrey.ukfsn.org> X-Archives-Salt: dd1b8d0a-e302-4c9f-81a3-9a3727db97c8 X-Archives-Hash: bf1945bdc8550105095e1c6ce8ed4909 On Thursday 30 September 2010 14:10:42 Florian Philipp wrote: > An HDD gets slower when you read the inner tracks. The angular > velocity is constant (5400 RPM) while the tangential velocity gets > lower with the radius. Are you telling us that the length of a stored bit is constant? I'd have thought it was the time needed to read or write a bit that was constant; otherwise the electronics would get extremely complex. In that case it's the angular velocity that counts, not the linear velocity, and it matters not which track your data are on. (If a block goes past the head twice as fast, it also occupies twice the space, so you're back where you were.) That's the way it was with our imposing new 2MB disks in 1974, anyway. They occupied boxes four feet tall and six feet long, and had external air systems; I was one of those responsible for the maintenance; we were sent on a training course specifically for the disks. I can't remember who made them, but they were part of a Ferranti Argus 500 system at the then national grid control centre. Maybe technology has changed since then. -- Rgds Peter. Linux Counter 5290, 1994-04-23.