paul_koning at Dell.com
Fri Jul 1 17:21:54 UTC 2011
On Jul 1, 2011, at 1:16 PM, Guy Harris wrote:
> On Jul 1, 2011, at 10:08 AM, Paul Eggert wrote:
>> This is a tricky business, though, since NTP does adjust the
>> the clock *frequency*, and CLOCK_MONOTONIC is *not* supposed
>> to be immune to *that*. If you want your elapsed-time measurements
>> to be more reliable in the presence of clock-frequency adjustments,
>> you need something fancier, e.g., GNU/Linux's CLOCK_MONOTONIC_RAW.
> If you care *that* much, you need something fancier, e.g. an atomic clock. :-) I seem to remember some news article in the past year or so indicating that there might be some new type of atomic clock coming out that would be less expensive, but I can't seem to find it with some simple Googling.
There was a new clock that's particularly compact (an inch or so max dimension). It wasn't clear just how it works, but it sounded like it's comparable in stability to a rubidium clock.
In the meantime, I think the cheapest atomic time source is a GPS box.
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