Date: Tue, 30 Jan 2001 12:10:25 +0100 From: Poul-Henning Kamp <phk@critter.freebsd.dk> To: thomas@hentschel.net Cc: Peter Wemm <peter@netplex.com.au>, Mark Huizer <freebsd@dohd.org>, freebsd-hackers@FreeBSD.ORG Subject: Re: Clustering FreeBSD Message-ID: <30257.980853025@critter> In-Reply-To: Your message of "Tue, 30 Jan 2001 03:03:40 PST." <200101301103.f0UB3f144218@falcon.home.hentschel.net>
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In message <200101301103.f0UB3f144218@falcon.home.hentschel.net>, thomas@hentschel.net writes: >>> What am I doing wrong? Given a diameter of appr. 7cm, I'd come at appr >>> 0.7Mach. Does that mean that within a few years my machine will go >>> KABOOM when booting? >> >> I have a 15K rpm drive if you want to do a recalculation. I think that >> is 1.05Mach, depending on whether you rounded or not. ;-) > >Hang on, there's a bug here somewhere: > >7cm = .07m, >.07m x 3.14... = .22m (per rotation) >.22m *15000/60 = 55m/s or ~ 195km/h or 123 mph, not even close to a fast car. > >We should expect breaking the sound barrier with >75krpm drives >(depending on your altitude and air pressure) That is overlooking that the air rotates in mostly laminar fashion with the platters, isn't it ? -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 phk@FreeBSD.ORG | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message
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