A set of general-purpose workstations (or even a PC) is used as a cheap variant of a massively parallel computer. One of the standard network technologies (Fast / Gigabit Ethernet, Myrinet) based on a bus architecture or a switch is used to communicate nodes. When clustering computers of different capacities or different architectures into a cluster, they talk about heterogeneous (heterogeneous) clusters.
NT cluster in NCSA, Beowulf clusters. NT Beowulf cluster
Cluster nodes can simultaneously be used as user workstations. In the case when it is not necessary, the nodes can be substantially lightened and / or installed in a rack.
Standard operating system operating systems are used, most often freely distributed - Linux / FreeBSD, together with special tools supporting parallel programming and load distribution.
Programming is usually in the context of the message passing model (most often MPI). The cheapness of such systems results in large overhead costs for the interaction of parallel processes with each other, which greatly narrows the potential class of problems to be solved. Standard operating system operating systems are used, most often freely distributed - Linux / FreeBSD, along with special tools supporting parallel programming and load balancing. MPI