In this paper we discuss the performance prediction of Fortran constructs commonly found in numerical scientific computing. Although the approach is applicable to multi-processors in general, within the scope of the paper we will concentrate on the Alliant FX/8 multiprocessor. The techniques proposed involve a combination of empirical observations, architectural models and analytical techniques, and exploits earlier work on data locality analysis and empirical characterization of the behavior of memory systems. The Lawrence Livermore Loops are used as a test-case to verify the approach.