OCAS is a computer cluster for HPC (high-performance computing) in astrophysics built during the years 2005 - 2007 at the Astronomical Institute of the Czech Academy of Science in Ondřejov. It is used above all for parallel execution of demanding numerical simulations using MPI parallel environment.
The cluster consists of 16 double-processor, 4 quad-core and 4 oct-core working nodes (i.e. 80 CPU cores in total), and the master workstation which serves as the user interface (login node), queue master, and the disc server. Further information on hardware and software used, as well as users guides can be found in respective sections of this website. Some documents are accessible only from the institute internal network.