The 3-D rigid-plastic finite element method using a diagonal matrix was applied to parallel processing using a distributed memory type PC cluster. The cluster composed of cheap PCs becomes common as a low-cost system in the parallel processing. Since the computers in the distributed memory type PC cluster have individual memory units, the transfer of date among computers during the computation is required, and thus the time for the data transfer is taken into consideration. The renewal of data in each computation is limited because of the time of data transfer unlike the shared memory type workstation. This brings about the delay of data renewal. A data transfer scheme was investigated to optimize the total computational time in the parallel processing. The effect of the delay of date renewal on the convergence of the solution was examined in the simulation of upsetting of rectangular block with an inclined tool by means of a cluster composed of 4 PCs and 100MBit/s Ethernet.