From owner-freebsd-hackers Tue Jan 30 2:41:15 2001 Delivered-To: freebsd-hackers@freebsd.org Received: from mailhub.fokus.gmd.de (mailhub.fokus.gmd.de [193.174.154.14]) by hub.freebsd.org (Postfix) with ESMTP id E599437B6C8 for ; Tue, 30 Jan 2001 02:40:55 -0800 (PST) Received: from beagle (beagle [193.175.132.100]) by mailhub.fokus.gmd.de (8.8.8/8.8.8) with ESMTP id LAA29589; Tue, 30 Jan 2001 11:40:37 +0100 (MET) Date: Tue, 30 Jan 2001 11:40:37 +0100 (CET) From: Harti Brandt To: Peter Wemm Cc: Mark Huizer , freebsd-hackers@FreeBSD.ORG Subject: Re: Clustering FreeBSD In-Reply-To: <200101301026.f0UAQJ463985@mobile.wemm.org> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG On Tue, 30 Jan 2001, Peter Wemm wrote: PW>Mark Huizer wrote: PW>> > | PW>> > | Doh! I mean 9.8 m/s/s, of course. PW>> > PW>> > That's acceleration not velocity :-) PW>> > PW>> > The terminal velocity of a PC case is probably a lot lower than the PW>> > velocity of an outer edge of a 10000 RPM drive. PW>> > PW>> What am I doing wrong? Given a diameter of appr. 7cm, I'd come at appr PW>> 0.7Mach. Does that mean that within a few years my machine will go PW>> KABOOM when booting? PW> PW>I have a 15K rpm drive if you want to do a recalculation. I think that PW>is 1.05Mach, depending on whether you rounded or not. ;-) Well, 7cm gives 21cm per rotation or 2.1km for 10000 rotations. 10000 Rotations Per Minute give around 130km per hour which is somewhere around 0.1MACH. So I expect not problems until the drives reach 50000 rpm :-) harti -- harti brandt, http://www.fokus.gmd.de/research/cc/cats/employees/hartmut.brandt/private brandt@fokus.gmd.de, harti@begemot.org, lhbrandt@mail.ru To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message