The hardware of the compute servers mirrors the development in high performance computing in the last years. Before around 2005 complex hardware from companies like IBM or SGI used to deliver the best performance. An example is the still present, but not powered on SGI Altix 3700. After that low cost clusters with fast interconnect (Myrinet or Infiniband) became more frequently used. Systems with AMD processors had a technological advantage due to the memory architecture of the Opteron systems. The clusters 1-6 fall into that category. But with the introduction of the Nehalem achritecture, which adapted some of the features of the AMD systems, Intel systems are again more suitable for high performance computing. The clusters 7, 8, 10, 11 and 12 fall into that category.