Limitations of performance of Exascale Applications and supercomputers they are running on

Abstract: The paper highlights that the cooperation of the components of the computing systems receives even more focus in the coming age of exascale computing. It discovers that inherent performance limitations exist and identifies the major critical contributions of the performance on many-many processor systems. The extended and reinterpreted simple Amdahl model describes the behavior of the existing supercomputers surprisingly well, and explains some mystical happenings around high-performance computing. It is pointed out that using the present technology and paradigm only marginal development of performance is possible, and that the major obstacle towards higher performance applications is the 70-years old computing paradigm itself. A way to step forward is also suggested