S. Wiesand (DESY)
64-Bit commodity clusters and farms based on AMD technology meanwhile have been proven to achieve a high computing power in many scientific applications. This report first gives a short introduction into the specialties of the amd64 architecture and the characteristics of two-way Opteron systems. Then results from measuring the performance and the behavior of such systems in various Particle Physics applications as compared to the classical 32-Bit systems are presented. The investigations cover analysis tools like ROOT, Astrophysics simulations based on CORSIKA and event reconstruction programs. Another field of investigations are parallel high performance clusters for Lattice QCD calculations, and n-loop calculations based on perturbative methods in quantum field theory using the formula manipulation program FORM. In addition to the performance results the compatibility of 32- and 64-Bit architectures and Linux operating system issues, as well as the impact on fabric management are discussed. It is shown that for most of the considered applications the recently available 64-bit commodity computers from AMD are a viable alternative to comparable 32-Bit systems.