OpenMPI vs MPICH2

[Satish Balay]

On Wed, 21 Jan 2009, #DOMINIC DENVER JOHN CHANDAR# wrote:

> Dear PETSc Users,
>  
>  Has anyone observed any specific improvement in computational speed
> while using the OpenMPI implementation compared to MPICH2 ? ( Or the
> other way around ?)..  Could it be problem dependent if there is a
> difference in speed ?

I don't have any comparison results. However here is my opinion.

Based on the hardware & network you have - you would have to check
with both impls [they do have mailing lists to help] - the best way to
configure & install it for that give hardware [i.e SMP?] & network.

[for eg: mpich configure supports options like --with-device
--with-channel - that results in different types of codes being used].

Once you the optimal install of each of these impls - you would have
to do a comparision for the app that matters.

Satish