Hello everyone, When I ran the same petsc codes on different clusters many times, one cluster always produces the same results, while the other one varies in terms of number of iterations for SNES and KSP convergence. If the problem is ill-conditioned, the round-off errors may cause different number of iterations to converge. However, what puzzles me is that the number of iterations on one machine is always the same while the other varies. I use same codes with same version of PETSc. The differences I can think about are MPI implementations (mvapich2 vs openmpi), compiler (icc vs gcc) and the network between the nodes. Could these factors cause these different behaviors?
Thank you. Best, Xiangdong
