Network interface for message-passing parallel computation on a workstation cluster

As commercial microprocessors become increasingly popu- lar in current MPP architectures, high-performance com mercial workstations have also received increased attention as cost-effective building@blo&s for large parallel-processing systems. The Fast User-level Network (FUNet) project (111 is an attempt at constructing an inexpensive workstation based parallel system capable of supporting efficient ex ecution of message-passing parallel programs. Based on MIT's Arctic 15) network technology, FUNet connects stock configured commodity workstations with a high-bandwidth packet-switched routing network. The Past User-level Net work Interface (FUNi) is the custom hardware network interface device that provides access to FUNet for both message passing and remote direct-memory-access (DMA) block transfers between parallel peer processes on FUNet connected workstations. The FUNi hardware mechanisms allow direct low-overhead user-level accesses to FUNet while maintaining secure and transparent sharing of FUNet among multiple parallel applications. FUNi can be realized as SBus peripheral cards to allow compatibility with a variety of workstation platforms. The relaxed clock speed (25MHz max.) of SBus allows FUNi to be inexpensively imple mented using FPGA parts that are synthesized from de sips captured in Verilog Hardware Description Language [15]. SBus's Direct Virtual Memory Access (DVMA)[8J also assists FUNi in overcoming the performance limitations im posed by existing workstation designs. Simulation results have shown that FUNet with FUNi, when coupled with latency-hiding software techniques, is effective in supporting fine-gra@ined parallel processing on a workstation cluster.