By: tarlinian (tarlinian.delete@this.gmail.com), January 24, 2017 9:58 am
Room: Moderated Discussions
Niels Jørgen Kruse (nj_kruse.delete@this.me.com) on January 23, 2017 10:41 pm wrote:
> Aaron Spink (aaronspink.delete@this.notearthlink.net) on January 23, 2017 7:01 pm wrote:
> > Niels Jørgen Kruse (nj_kruse.delete@this.me.com) on January 22, 2017 12:16 pm wrote:
> > > In weather prediction, you do ensemble runs anyway.
> > >
> > >
> >
> > Because it is a statistical model, but now you have to do backup runs for each of your
> > ensemble runs because you don't know how out of whack they got from memory errors.
> > In any reasonable sized super, you are going to have daily/hourly memory errors.
>
> It would be more rational to increase the ensemble. It doesn't
> matter why any particular run deviates from the majority.
That really doesn't make physical sense. The "noise" generated by random bit flips likely comes from a completely different distribution than the noise that the "noise" that results from initial condition perturbations.
> Aaron Spink (aaronspink.delete@this.notearthlink.net) on January 23, 2017 7:01 pm wrote:
> > Niels Jørgen Kruse (nj_kruse.delete@this.me.com) on January 22, 2017 12:16 pm wrote:
> > > In weather prediction, you do ensemble runs anyway.
> > >
> > >
> >
> > Because it is a statistical model, but now you have to do backup runs for each of your
> > ensemble runs because you don't know how out of whack they got from memory errors.
> > In any reasonable sized super, you are going to have daily/hourly memory errors.
>
> It would be more rational to increase the ensemble. It doesn't
> matter why any particular run deviates from the majority.
That really doesn't make physical sense. The "noise" generated by random bit flips likely comes from a completely different distribution than the noise that the "noise" that results from initial condition perturbations.