REDUCTION PROCESSING METHOD FOR PARALLEL COMPUTER, AND PARALLEL COMPUTER

A reduction processing method for a parallel computer, and the parallel computer are provided to enable each node to transfer n-divided data to other nodes, integrate and compute the data by 1/n, and transfer each computation result to an integrated node, thereby realizing transmission processing at high speed and shortening a transmission time. A parallel computer comprises the followings: three or more nodes(10,11,12,13) which separately have a plurality of network adapters(A,B,C); and cross bar switches which connects the network adapters of each of the nodes. Each node divides held data into plural data and transfers the divided data to plural other nodes through different network adapters respectively. Each of the nodes executes the reduction operation of received divided data and the held data, and the plural nodes transfer the reduction operation result to at least one of the nodes through the network adapter and integrate the data.