[ntp:questions] Red Hat vote for chrony

Paul tik-tok at bodosom.net
Wed Dec 10 14:58:36 UTC 2014

On Wed, Dec 10, 2014 at 5:04 AM, Miroslav Lichvar <mlichvar at redhat.com>

> See also the following post, apparently the BBB can use a separate HW
> timer to timestamp PPS, reducing the error and jitter significantly.
> http://blog.dan.drown.org/beaglebone-black-timer-capture-driver/
> It looks like this could be a really nice and cheap NTP/PTP server.

Here's Dan's post to time-nuts about this <
He provided two more graphs. Apropos our subject he uses Chrony.
There are some other people doing PRU and timer capture on the Black as
well as external clocking.
Hence my earlier reference to it if one wanted to continue in the spirit of
the 4501 mods.
Only without modifying a motherboard.

Of course Ackerman's graphs makes it obvious that having nanosecond errors
on your servers is irrelevant once you're outside the box.
People are also working on PTP so you might actually be able to build a
nice clock for $250 in materials.

Here's Simon Marsh's hardware mod a la the PHK/Ackerman 4501 on the BBB if
you want skip external clocking.

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