In message <[EMAIL PROTECTED]>, Jim Bryant writes:

>since there is only a single master clock oscillator, there really
>should be no frequency difference between CPUs.

As long it runs constantly: yes.  As soon as you have clock-stop
events you will have different resync times for the on-chip PLLs.

>Ideally, motherboards should be
>designed to have equal length clock lines to each CPU, 

They are, but that doesn't mean that the PLL'ed core frequencies
are in lockstep when the clocks change.

>the current price of accurate TCXOs is low enough to be economical in
>PCs, and these seriously reduce the drift compared to the cheezy TTL
>clocks currently used.

There are no cheesy TTL clocks used.  There are random encapsulated
rock with pretty high-quality drive circuitry and PLL generation
of all sorts of other frequencies.

>speaking of atomic breakdown...  they could start making cheaper
>cesium-beam tubes given the current level of the nuclear waste issue

The actual amount of Cs in the Cesium unit has no cost impact.  There
are man components of a Cs unit which carry significantly higher
pricetags than the few grammes of Cs.  A un-optimally constructed
Cs is worse than a low-cost Rb unit.

>Cesium beam tubes are essentially extremely accurate
>narrow bandwidth filters, and not oscillators.

It is neither.

>with russia having made two seperate threats of aggression to destroy
>the entire planet with nuclear weapons in the past twelve months [...]

Lets not get too far from the topic, OK ?

Poul-Henning Kamp             FreeBSD coreteam member
[EMAIL PROTECTED]               "Real hackers run -current on their laptop."
FreeBSD -- It will take a long time before progress goes too far!

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