Performance evaluation of sparse matrix multiplication kernels on intel xeon phi

Abstract. Intel Xeon Phi is a recently released high-performance co-processor which features 61 cores each supporting 4 hardware threads with 512-bit wide SIMD registers achieving a peak theoretical perfor-mance of 1Tflop/s in double precision. Its design differs from classical modern processors; it comes with a large number of cores, the 4-way hyperthreading capability allows many applications to saturate the mas-sive memory bandwidth, and its large SIMD capabilities allow to reach high computation throughput. The core of many scientific applications involves the multiplication of a large, sparse matrix with a single or mul-tiple dense vectors which are not compute-bound but memory-bound. In this paper, we investigate the performance of the Xeon Phi coprocessor for these sparse linear algebra kernels. We highlight the important hard-ware details and show that Xeon Phi’s sparse kernel performance is very promising and even better than that of cutting-edge CPUs and GPUs.