Petascale Parallelization of the Gyrokinetic Toroidal Code

The Gyrokinetic Toroidal Code (GTC) is a global, threedimensional particle-in-cell application developed to study microturbulence in tokamak fusion devices. The global capability of GTC is unique, allowing researchers to systematically analyze important dynamics such as turbulence spreading. In this work we examine a new radial domain decomposition approach to allow scalability onto the latest generation of petascale systems. Extensive performance evaluation is conducted on three high performance computing systems: the IBM BG/P, the Cray XT4, and an Intel Xeon Cluster. Overall results show that the radial decomposition approach dramatically increases scalability, while reducing the memory footprint — allowing for fusion device simulations at an unprecedented scale. Research Topics: Large scale simulations in CS&E, parallel and distributed computing, performance analysis