Am 25.08.2018 um 18:10 schrieb William F Pokorny:

> A reason I suggested the grep command is I wonder if all the cores are
> maxed out with respect to the multipliers. Are some cores in fact being
> throttled? The 3.8ghz number is a core seeing a 10x 100Mhz but you can
> get up to 12x 100MHz on a core. I don't know if thermal throttling is by
> core or by die.

Where do you get those numbers from?

From all I know (and what a quick random peek at the internet
confirmed), CPU speed is per core, not per package.


> I further wonder how constant the reported 3.8GHz number really is. On
> my i3 the frequency values reported in /proc/cpuinfo look to be
> relatively instantaneous. I'm not under load and those MHz values change
> dramatically every time I look. I think we'd need to monitor the
> performance over time for a full image render to be sure the 3.8GHz held.

What you might be seeing is the CPU not throttling due to overheating,
but due to being bored.

Also, if this is a per-CPU speed, it may be averaging over all cores,
even cores shut down entirely due to being bored.


> My thinking is 2.8GHz is the performance Intel can guarantee under all
> loads given the manufacturing process variation and shipped cooling at
> some expected "end of life." Otherwise, they'd be claiming a better base
> performance & charging for it, or, somehow handicapping the CPUs aimed
> at lower end boxes so as not to eat into their higher end - higher
> profit - business.

Certainly. At the miniscule dimensions they're currently working at, I'd
be surprised if their tests could catch all the bad apples; so it's
reasonable to assume that they're working with safety margins, and
rating the CPUs for the worst case scenario.

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