Knowing Issues

Under OpenMPI (now MPICH2 as well), R slaves will use 100% CPU time while waiting for master's instructions. This is mainly caused by OpenMPI's blocking call implementations. Under LAM R slaves use 0% CPU time while waiting. However, staring from Rmpi 0.6-1, you can use mpi.spawn.Rslaves() without this issue since nonblock procedure is used as default..