[Beowulf] Hyperthreading and 'OS jitter'

[John Hearns]

Scott, Evan, Nathan
those are some really thought provoking answers.
Evans point about cloud providers is especially interesting - as we are
seeing more and more Openstack being used in private clouds , to create
clusters 'on demand' we should be aware of this.

And regarding the point "I'm not an expert in fab economics, but I don't
believe it would not significantly add to production costs."
Errr... I admit my ignorance too, though I should  know a lot more as I am
currently working with ASML - who make advanced semiconductor lithography
machines!






On 26 July 2017 at 00:20, Nathan Moore <ntmoore at gmail.com> wrote:

> ​​
>
>>
>> Re: having a specialized, low-power core, this is clearly something
>> that's already been successful in the mobile device space. The big.LITTLE
>> <https://en.wikipedia.org/wiki/ARM_big.LITTLE> ARM architecture is
>> designed for this kind of thing and has been quite successful. Certainly,
>> now that Intel and AMD are really designing modular SoC-like products, it
>> wouldn't be terribly difficult to bake in a couple of low power x86 cores
>> (e.g. Atom or Xeon-D + larger Skylake die in Intel's case; Jaguar + Zen in
>> AMD's case). I'm not an expert in fab economics, but I don't believe it
>> would not significantly add to production costs.
>>
>
> T​he​
> ​ "textbook" answer​ to integrated circuit manufacturing is that there
> need be no dependence of device cost on number of gates/device complexity.
> Fundamentally, you're just printing/etching a slightly more complicated
> mask on a circuit board.  The number of gates and the probability of
> defects are probably proportional - didn't AMD sell 6 and 3 core processors
> for a while?  I always assumed those were 4 or 8 core procs that had
> critical defects in one of the cores.  Sorry, no first-hand knowledge
> though.
>
> Jim Lux probably knows the real answer.
>
>
> ​Nathan​
>
>
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