[time-nuts] Re: When did computer clocks get so bad?

[Poul-Henning Kamp]

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Alec Teal writes:

> My theory is that super cheap crappy quartz clocks are now used in 
> things which can be reasonably expected to be online most of the time, 

There are multiple answers to your question.

The funny one is:  When they set fire to a prototype motherboard
at Intel Architecture Labs.

Unfortunately that is not my story to tell.

But for the PC-ecosystem, that really is the answer:

When Intel had to start modulating clock-frequency in order to not
set things on fire.

Their execution was far from stellar, because they had their eyes
only on Windows, which for all intents and purposes had no timekeeping
worth anything at the time.

By now they have it relatively under control, and due to the very
steep PLL multipliers high end kit actually have comparatively
good XTALS in order to keep the jitter within spec.

For the Internet of Shit segment, the answer is it was never any
good to begin with.

Since these embedded chips generally are incredibly robust with
respect to timing, the xtal on the BOM is the cheapest that will
meet spec.

The one saving grace is external high-speed interfaces like USB-3
and 10G ethernet:  You need good-ish xtals before it even works.

-- 
Poul-Henning Kamp       | UNIX since Zilog Zeus 3.20
phk at FreeBSD.ORG         | TCP/IP since RFC 956
FreeBSD committer       | BSD since 4.3-tahoe    
Never attribute to malice what can adequately be explained by incompetence.