How Vector Processors Work: An Example Best to understand a vector processor by looking at a vector loop for RV64V. Let's take a typical vector problem, which we use throughout this section: Y = a X Y X and Y are vectors, initially resident in memory, and a is a scalar. This problem is the SAXPY or DAXPY loop that forms the inner loop of the Linpack benchmark (Dongarra et al., 2003). (SAXPY stands for single-precision aX plus Y, and DAXPY for double precision aX plus Y.) Linpack is a collection of linear algebra routines, and the Linpack benchmark consists of routines for performing Gaussian elimination. For now, let us assume that the number of elements, or length, of a vector register (32) matches the length of the vector operation we are interested in. (This restriction will be lifted shortly.)