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Subject: Re: [OMPI users] MPI_Reduce performance
From: Gabriele Fatigati (g.fatigati_at_[hidden])
Date: 2010-09-09 03:11:51


Hy Terry,

this time is spent in MPI_Reduce, it isn't total execution time.

2010/9/9 Terry Frankcombe <terry_at_[hidden]>

> Gabriele,
>
> Can you clarify... those timings are what is reported for the reduction
> call specifically, not the total execution time?
>
> If so, then the difference is, to a first approximation, the time you
> spend sitting idly by doing absolutely nothing waiting at the barrier.
>
> Ciao
> Terry
>
>
> --
> Dr. Terry Frankcombe
> Research School of Chemistry, Australian National University
> Ph: (+61) 0417 163 509 Skype: terry.frankcombe
>
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>

-- 
Ing. Gabriele Fatigati
Parallel programmer
CINECA Systems & Tecnologies Department
Supercomputing Group
Via Magnanelli 6/3, Casalecchio di Reno (BO) Italy
www.cineca.it                    Tel:   +39 051 6171722
g.fatigati [AT] cineca.it