[petsc-users] [petsc-maint #78993] Re: MPI v. Pthreads ?

[Barry Smith]

On Jul 10, 2011, at 1:02 PM, John Chludzinski wrote:

> So if host the "new and improved" PETSc on a mult--proc/multi-core Linux
> workstation (or in my case, a mult--proc/multi-core Windows workstation
> running Cygwin), not configured as a cluster, I would be using pthreads and
> not MPI?

    You can mix and match. One MPI process and a bunch of threads or two (or more) MPI processes each using some threads.

   Barry

> 
> ---John
> 
> 
> On Sun, Jul 10, 2011 at 12:45, John Chludzinski <jchludzinski at gmail.com>wrote:
> 
>> You mentioned: "pthread based Vec and Mat class that lives inside the PETSc
>> MPI world".  Is this pthreads *in lieu of* MPI or is it pthreads *in
>> addition to* MPI?
>> 
> 
> The latter. Pthreads within a NUMA node or shared memory node, MPI between
> nodes.
>