Multi-CPU plasma fluid turbulence calculations on a CRAY Y-MP C90

Significant improvements in real-time efficiency have been obtained for plasma fluid turbulence calculations by microtasking the nonlinear fluid code KITE in which they are implemented on the CRAY Y-MP C90 at the National Energy Research Supercomputer Center (NERSC). The number of processors accessed concurrently scales linearly with problem size. Close to six concurrent processors have so far been obtained with a three-dimensional nonlinear production calculation at the currently allowed memory size of 80 Mword. With a calculation size corresponding to the maximum allowed memory of 200 Mword in the next system configuration, the authors expect to be able to access close to ten processors of the C90 concurrently with a commensurate improvement in real-time efficiency. These improvements in performance are comparable to those expected from a massively parallel implementation of the same calculations on the Intel Paragon.