[petsc-dev] PETSc and threads

[Barry Smith]

> On Jan 8, 2015, at 2:47 PM, Mark Adams <mfadams at lbl.gov> wrote:
> 
> I have a project that needs to show a plan for moving the the new ORNL machine SUMMIT

  Isn't Summit IBM PowerN + Nvidia GPUs with a huge percentage of the available floating point performance only available from the GPUs? Thus utilizing the machine means much more utilizing GPUs than utilizing "threads" on the PowerN? 


> and I wanted to see if there is any writeup or data with respect to thread performance in PETSc.

   We've never run the thread code of PETSc on PowerN (I suspect it would be fairly good but PowerN systems are too expensive to buy to test with :-)).

   Regardless the "thread performance" will depend to first and second order only on the memory bandwidth available to the threads.

  Barry

> 
> Thanks,
> Mark