Master thesis defense by Timo Vinke

The Copenhagen Langevin Spin Simulation Code (CLaSSiC) is a simulation suite developed to investigate the absolute temperature effects in frustrated spin systems. Previous versions of CLaSSiC were not fast enough to run system sizes on the order of 10.000 atoms. This report aims to increase its performance to a level where it can run these systems overnight, which would mean a 400x speedup. This will be done by rewriting it in C++ and making better use of the available hardware. To
verify the level of optimization, Intel Vtune is used. It shows that there are still unoptimized sections, such as the Gaussian number generation. Afterwards the model has been validated thoroughly to check if it corresponds to theory, which it does. Overall the optimization has been successful and CLaSSiC is now almost 10.000 times faster, running system sizes of 10.000 atoms in under 20 minutes.