Cluster Design in the Earth Sciences Tethys

Computational modeling is a powerful tool in the Earth Sciences. In the solid Earth important simulation areas include seismic wave propagation, rupture and fault dynamics in the lithosphere, creep in the mantle, and magneto-hydrodynamic flow linked to magnetic field generation in the core. These problems rank among the most demanding calculations computational physicists can perform today. They exceed the limitations of the largest high-performance computing systems by a factor of ten to one hundred measured both in terms of the demands on capacity and capability of systems. Off-the-shelf high-performance Linux clusters are useful to ease the limitations in capacity computing by exploiting price advantages in mass produced PC hardware. Here we review our experience of building a 128 processor AMD Opteron Gigabit Ethernet Linux cluster. The machine is operated at the scientific department level, targeted directly at large-scale geophysical and tectonic modeling and is funded by the German Ministry of Education and Science and the Free State of Bavaria. We observe an aggregate system performance of 140 GFLOPs out of a theoretical 624 GFLOPs peak.