Parallel magnetohydrodynamics on the CM-5

The equations of magnetohydrodynamics (MHD) describe the interaction of hot ionised gases (plasmas) with magnetic fields. MHD phenomena basically involve 3D time-dependent structures characterised by the simultaneous presence of both very fine-scale and global variations in a complex magnetic field geometry evolving on a number of vastly different time scales. The parallelism (performance and scalability) of the essential building blocks of MHD codes (FFTs, matrix-vector multiplications, inner products, etc.) is studied on the CM-5.