Calculable black holes
Cluster computers based on Intel Xeon architecture at the Albert Einstein Institute are now twice as fast
Almost 100 years after Albert Einstein developed the theory of relativity, our knowledge of gravitational physics has grown rapidly. Einstein, for example, had strong reservations about the existence of black holes. Today we are certain that they exist. This certainty regarding black holes is due, inter alia, to advances in computer research. Ever faster computers today enable scientists to test complex concepts and theories of gravitational physicists by simulating realistic astrophysical systems and visualizing them three-dimensionally.
At the Max Planck Institute for Gravitational Physics (Albert Einstein Institute, AEI) in Potsdam-Golm, an international centre of relativity, some of the leading minds of gravitational physics are to be found.
For the highly complex numerical simulations of black holes, ever greater demands are placed on computing power, storage capacity, and the network speed of the computers used. For this type of computation the AEI uses the PEYOTE cluster computer, which was doubled to 128 computer nodes at the end of 2003, thereby allowing users to further refine their model calculations. The support of INTEL made it possible to test the latest processor of the company, a P4 Xeon with 3.06GHz and 1MB 3rd Level Cache. This was undertaken before the official launch of the product, so that one could balance possible increases in performance by using this type of processor against the additional costs. The latest developments in the design of the expansion could also be taken into account thereby. This year a further expansion to 256 PC nodes is planned for the cluster; later an increase to 1024 processors is planned.
The main users of the cluster are the scientists in the Department of Astrophysical Relativity and, in particular, the Numerical Relativity Group. However, scientists from other groups and cooperating partners are also users of this high-performance cluster. Especially close ties exist with Prof. Dr. Ed Seidel, the Director of the Center for Computation and Technology at Louisiana State University (LSU) in Baton Rouge and former head of the Numerical Relativity Group at the AEI. Prof. Seidel, who still continues to work at AEI in combination with his position at LSU, emphasizes: "This collaboration enables our groups to continue at the vanguard of research on black hole physics. By pooling resources at AEI and at Louisiana State University, we are also creating a powerful grid environment for collaborative research."
The cluster is particularly suitable for problems that can be parallelized. These are matrix operations, as they are also primarily used for simulations. In such instances, the individual nodes of the cluster must be able to communicate with one another with particular speed and effectiveness. The main research area of the Numerical Relativity Group is the calculation of the Einstein equations for astrophysically interesting cases such as the collision of black holes or neutron stars. The results of these simulations are visualised either on the head node of the cluster or on workstations that are particularly suitable for graphics output.
The Max Planck Institute for Gravitational Physics
The Max Planck Institute for Gravitational Physics (Albert Einstein Institute) in Potsdam-Golm has established itself as a leading international research centre for gravitational physics since it was founded in 1995. Over 90 scientists and more than 150 visitors each year investigate all aspects of gravitational physics.