Abstract: A system and method for connecting computer workstations in clusters to perform parallel-distributed processing with respect to compute-intensive applications are provided. Commodity computers/workstations and commodity network hardware are arranged to form unique-architecture building blocks (clusters) which may then act as supernodes in larger scale cluster systems. An integrated ROCC+ (Reduced Overhead Cluster Communication) message passing software system provides unique communication logic for efficient implementation of collective message passing operations between each node and supernode. According to a preferred embodiment, each building block comprises two ethernet segments and four nodes (e.g., workstations), two of which are connected by Network Interface Cards (NICs) to both segments with the remaining nodes each connected to a respective one of the segments.