Optimization of Lattice QCD codes for the AMD Opteron processor

We report our experience of the optimization of the lattice QCD codes for the new Opteron cluster at DESY Hamburg, including benchmarks. Details of the optimization using SSE/SSE2 instructions and the effective use of prefetch instructions are discussed.Comment: 5 pages, 4 figures, espcrc2.cls, Proceedings of X International Workshop on Advanced Computing and Analysis Techniques in Physics Research (ACAT 2005), DESY Zeuthen, Germany, May 22 - 27, 200