Porting the 3D gyrokinetic particle-in-cell code GTC to the NEC SX-6 vector architecture: perspectives and challenges

Several years of optimization on the cache-based super-scalar architecture has made it more difficult to port the current version of the 3D particle-in-cell code GTC to the NEC SX-6 vector architecture. This paper explains the initial work that has been done to port this code to the SX-6 computer and to optimize the most time consuming parts. After a few modifications, single-processor results show a performance increase of 5.2 compared to the IBM SP Power3 processor, and 2.7 compared to the Power4. [Copyright &y& Elsevier]