Amesos, AztecOO, Belos: Increasing number of threads leads to decrease of performance
Created by: freaklovesmango
My general goal is to accelerate the process of solving systems of linear equations by exploiting parallel libraries which work on shared-memory systems. That is why I tried Trilinos. More specific, I used Amesos (with PARDISO), AztecOO and Belos. All with Epetra as the underlying linear algebra package and without MPI at all. I change the number of threads with OMP_THREADS_NUMBER and the input matrices I used have dimensions more than 175,000.
The overall observation was that with increasing number of threads the execution time get worse. So I just wanted to see if you may have hypothetical answers or more like ideas in which directions I could go for looking for the answer. Maybe someone experienced similarly or completely different.