Dear PETSc developers, I installed OpenMPI3 first and then installed PETSc with that mpi. Currently, I'm facing a scalability issue, in detail, I tested that using OpenMPI to calculate an addition of two distributed arrays and I get a good scalability. The problem is when I calculate the addition of two vectors in PETSc, I don't have any scalability. For the same size of the problem, PETSc costs a lot much time than merely using OpenMPI.
My PETSc version is 3.16.0 and the version of OpenMPI is 3.1.4. Hope you can give me some suggestions. Best Regards, Yujie