Towards a portable, fast parallel APM-SPH code: HYDRA_MPI. HYDRA_MPI is a portable parallel N-body solver, based on the adaptive PM algorithm. This Fortran90 code is parallelised using a non-trivial task-farm and two domain decompositions: a 2D cycle of blocks and a slab distribution, using both MPI-1.1 and MPI-2 communications routines. Specifically, MPI_Put and MPI_Get are employed extensively in association with the communication epochs MPI_Fence and MPI_Lock/MPI_Unlock. The 1D FFTW is employed. We intend to extend the use of HYDRA_MPI to cosmological simulations that include Smoothed Particle Hydrodynamics.