Parix

PARIX (PARallel UnIX extensions) [12] is the native operating system on Parsytec GC systems. It provides UNIX functionality at the front-end with library extensions for the needs of the parallel system. The Parix software package comprises components for the program development environment (compilers, tools, etc.), runtime environment (libraries), multi-user administration, and control-net software. Parix is available for a variety of parallel Parsytec computers. At the Paderborn Center for Parallel Computing, we run Parix on

• a 1024-node transputer system GCel-1024, where the T805-nodes are interconnected in a 2-dimensional mesh topology,
• a medium size PowerXplorer with PowerPC 601 application processors and T805-transputers for the communication,
• a high-performance GC/PowerPlus, with two PowerPC-601 application processors and four T805 communication processors interconnected in a 2-dimensional fat mesh with 4 links in each direction.

A virtual topologies library [20,21] provides an optimal mapping of the application process structure onto the underlying hardware interconnection structure.

Based on the virtual topologies, common global communication functions like broadcast, global sum, min, max and barrier synchronization are available for groups of processes.

• Algorithm Architecture on Parix