[Bloat] Possibly interesting video on atomic clocks

Carsten Bormann cabo at tzi.org
Tue Aug 24 16:38:14 EDT 2021

On 2021-08-24, at 20:00, Michael Yartys via Bloat <bloat at lists.bufferbloat.net> wrote:
> https://www.youtube.com/watch?v=JK3eTGkX6qY

OMG.  Among other things, he says:

A cheap Rubidium clock module has a deviation of less than 1 second in 100 million years (that would be 3e-16!) (1).
Because it’s an atomic clock, it sure must be radioactive (2).
NTP gives you 400 ms deviations (3).

Well, that should be enough to laugh this whole thing off.


PTP is good (a), and support for it is in many chips (b).
It is useful to have a local time reference that is better than a crappy CPU clock crystal (c) (even if a Rubidium oscillator is overkill, in particular if you already have PTP to sync with — go for a cheap OCXO for a start).

Linus’ typical 254,481 views is going to get some attention to the question of precise clocks on computers — that is probably the only good coming from this video, together with complete garbage such as that your computer must be radioactive to give you a fair gaming experience.

Grüße, Carsten

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