Re: OpenMPI / MPI transition
Hi,
So I have pushed to salsa a commit switching mpi defaults for 32-bit
platforms to mpich.
https://salsa.debian.org/science-team/mpi-defaults
I propose to push this to unstable. I will hold off on any changes to
openmpi or mpich (except to experimental).
How do I do such a transition? I can't easily test as I lack 32-bit
hardware. It _should_ be fine as MPICH builds and works
So I'm seeking release team advice before proceeding.
Alastair
On 24/11/2023 15:34, Drew Parsons wrote:
On 2023-11-24 15:00, Alastair McKinstry wrote:
My understanding is that MPICH has been typically the reference
implementation, higher quality but less performant, particularly with
the range of fabrics. Certainly I've seen mostly OpenMPI but not MPICH
on various HPC machines. People would use either OpenMPI or a vendors
MPI (which may be forked MPICH with added network hardware support).
I took a straw poll in one of our upstream fora, and the reply there
was similar. The serious performance improvements come from the
fabrics drivers provided by the hardware manufacturers. So it doesn't
really matter too much which implementation we default to. I'm
comfortable moving to a mixed default, OpenMPI on 64 bit and MPICH on
32 bit or where needed.
Drew
--
Alastair McKinstry,
GPG: 82383CE9165B347C787081A2CBE6BB4E5D9AD3A5
e: mckinstry@debian.org, im: @alastair:mckinstry.ie
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