Evaluating the Performance of Basic Linear Algebra Subroutines on a Torus Array Processor

The basic linear algebra subroutines (BLAS) are standard operations to efficiently solve the linear algebra problems on high performance and parallel systems. In this paper, we study the implementation of some important BLAS operations on a NtimesN torus array processor. We show that the performance of the Level-3 BLAS represented by the nxn matrix multiply-add operation, n>N, approaches the theoretical peak as n increases since the degree of data reusing is high. While the performance of Level-1 and Level-2 BLAS operations is low as a result of low data reusing. Fortunately, many applications are based on intensive use of Level-3 BLAS with small percentage of Level-1 and Level-2 BLAS.