Date: Wed, 21 Feb 2007 07:29:21 +0000 From: Matthew Seaman <m.seaman@infracaninophile.co.uk> To: Alan Amesbury <amesbury@umn.edu> Cc: freebsd-stable@freebsd.org, Ivan Voras <ivoras@fer.hr> Subject: Re: getting garbage faster using FreeBSD? Message-ID: <45DBF4D1.6000708@infracaninophile.co.uk> In-Reply-To: <45DB8B8D.6080706@umn.edu> References: <20070220215248.3C22216D23E@hub.freebsd.org> <45DB8B8D.6080706@umn.edu>
next in thread | previous in thread | raw e-mail | index | archive | help
This is an OpenPGP/MIME signed message (RFC 2440 and 3156)
--------------enigBE410E47035F0530B35EA1E7
Content-Type: text/plain; charset=ISO-8859-15
Content-Transfer-Encoding: quoted-printable
Alan Amesbury wrote:
> Ivan Voras wrote:
>=20
>> The obvious question - why don't you burn the tapes and hammer the dis=
ks? :)
>=20
> Ah, low-tech. I know it well. Still, the last time I did any data
> destruction, I found a 4 Tesla magnet does wonders. Downsides:
>=20
> 1) Oxford's 90cm bore, helium-cooled magnets aren't that
> common, perhaps because a 2000V/500A power source
> is a bit expensive (solution doesn't scale).
It ain't the PSU that's the expensive bit on a supercon magnet -- it's th=
e
liquid Helium. After all, once you've ramped the current in the coil up =
to
$bignum amps, it just keeps going so long as the superconductors aren't
allowed to heat up. LHe costs about the same as good whiskey, and you nee=
d
gallons of the stuff every few weeks.
> 2) The hard drive has a tendency to fly out of one's
> hands while moving it through the lines of force
> (solution requires some physical coordination).
Hmmm.... a solenoid coil magnet has a field that is approximately dipolar=
=2E
Forces vary as the inverse *cube* of the distance away from the center of=
the magnet. Move a centimeter too close and the drive will suddenly be
ripped out of your hands harder than you can resist.
And sticking lumps of magnetic material up the bore of a 4T magnet
probably requires quenching the magnet in order to get it out without
damaging the magnet... Can you feel your accounts department wincing
yet?
> It's primarily for item #1 that I hadn't mentioned this earlier, as mos=
t
> readers of -STABLE users are probably looking for a more scalable solut=
ion.
Everyone should have their very own NMR spectrometer in their living room=
!
Cheers,
Matthew
--=20
Dr Matthew J Seaman MA, D.Phil. 7 Priory Courtyard
Flat 3
PGP: http://www.infracaninophile.co.uk/pgpkey Ramsgate
Kent, CT11 9PW
--------------enigBE410E47035F0530B35EA1E7
Content-Type: application/pgp-signature; name="signature.asc"
Content-Description: OpenPGP digital signature
Content-Disposition: attachment; filename="signature.asc"
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v2.0.2 (FreeBSD)
Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org
iD8DBQFF2/TX8Mjk52CukIwRCFsVAJ4qymkFzwHbDQALzM+6D8mcXnDfwACeLtzC
QFZ+dIEV+YDOg4zXgJQU4Ow=
=sju3
-----END PGP SIGNATURE-----
--------------enigBE410E47035F0530B35EA1E7--
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?45DBF4D1.6000708>