MPI/MBCF is a high-performance MPI library targeting a cluster of workstations connected by a commodity network. It is implemented with the Memory-Based Communication Facilities (MBCF), which provides software mechanisms for users to access remote task's memory space with o -the-shelf network hardware. MPI/MBCF uses Memory-Based FIFO for message bu ering and Remote Write for communication without bu ering from among the functions of MBCF. In this paper, we evaluate the performance of MPI/MBCF on a cluster of workstations with the NAS Parallel Benchmarks. We verify whether a message passing library implemented on the shared memory model achieves higher performance than that on the message passing model.