Performance Evaluation of Intel Xeon Phi Coprocessor using XKaapi

This paper presents preliminary performance comparisons of parallel applications developed natively for the Intel Xeon Phi accelerator using three different parallel programming environments and their associated runtime systems. We compare Intel OpenMP, Intel CilkPlus and XKaapi together on the same benchmark suite. Our benchmark suite is composed of two computing kernels: a Fibonacci computation that allows to study the overhead and the scalability of the runtime system, and a NQueens application generating irregular and dynamic tasks. Performance evaluation shows our XKaapi data-flow parallel programming environment exposes the lowest overhead of all and is highly competitive with native OpenMP and CilkPlus environments on Xeon Phi. Moreover, the efficient handling of data-flow dependencies between tasks makes our XKaapi environment exhibit more parallelism.