With financial support from NWO (open competition) we have built a network special purpose computer. By attaching small dedicated hardware to workstations we gain the flexibility, communication characteristics and the raw super-computing power required to simulate astronomical N-body systems with a realistic number of objects and with realistic physics.
The system, called MoDeStA (for Modeling Dense Stellar systems in Amsterdam) is currently operational and used to develop and study parallel N-body kernels, to analyze inhomogeneous hardware characteristics and to simulate astronomical N-body systems.
MoDeStA consists of a cluster of four 240 Gflops GRAPE-6A/2 special purpose computers setup in a 42-node Beowulf architecture. Each GRAPE node is attached to a normal 1.7GHz Athlon PC via a PCI-5V bus. The main advantage of this setup is the local supercomputer performance to simulate dense star clusters and the global Beowulf performance to simulate the environment in which the star cluster resides.
More information on this machine can be found at
http://carol.science.uva.nl/
spz/act/modesta/index.html
The MoDeStA platform and the web site is a virtual meeting place for astronomers and computational scientists (see also below under D).