[petsc-users] speedup for TS solver using DMDA

[Barry Smith]

   Please send the output from running 

    make steams NPMAX=32 

    in the PETSc root directory.


   Barry

  My guess is that it reports “one node” is just because it uses the “hostname” to distinguish nodes and though your machine has two CPUs, from the point of view of the OS it has only a single hostname and hence reports just one “node”.

   
On Sep 15, 2014, at 12:45 PM, Katy Ghantous <katyghantous at gmail.com> wrote:

> Hi, 
> I am using DMDA to run in parallel TS to solves a set of N equations. I am using DMDAGetCorners in the RHSfunction with setting the stencil size at 2 to solve a set of coupled ODEs on 30 cores.
> The machine has 32 cores (2 physical CPUs with 2x8 core each with speed of 3.4Ghz per core). 
> However, mpiexec with more than one core is showing no speedup.
> Also at the configuring/testing stage for petsc on that machine, there was no speedup and it only reported one node.  
> Is there somehting wrong with how i configured petsc or is the approach inappropriate for the machine? 
> I am not sure what files (or sections of the code) you would need to be able to answer my question. 
> 
> Thank you!