[rescue] In Realtime: Saving 25, 000 Manuals ??? August 15, 2015

Phil Stracchino phils at caerllewys.net
Fri Aug 21 12:21:25 CDT 2015

On 08/21/15 13:11, Bob Darlington wrote:
> But what's useful?  Do our filesystems use anything better than one second
> precision?  Surely a few hundred microseconds won't matter.  And it doesn't
> unless you're a time-nut.    These guys are used to measuring distance in
> nanoseconds (in particular, wire and cable lengths).  How temperature
> effects measurements.  It's very common for me to notice significant
> differences in measurements solely because of a temperature change in my
> lab.   It's a pain.

I hear you.  Practically speaking, it makes little difference whether
all of the (sync-able) clocks in the house are synced within a second or
within .01 second.

But from a geekish "Because I can" standpoint, and honestly from
perfectionism, I'd be much happier if they were all synced within at
least single-digit microseconds, and to a reference source that I know
remains accurate to at least that level even if my uplink goes down.
GPS starts to look really attractive from this standpoint because it can
provide near-atomic-clock levels of timekeeping accuracy for a
thousandth of the cost, and without requiring an environmentally
controlled isolation room.

  Phil Stracchino
  Babylon Communications
  phils at caerllewys.net
  phil at co.ordinate.org
  Landline: 603.293.8485

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