PROGRAPE-1: A Programmable, Multi-Purpose Computer for Many-Body Simulations

We have developed PROGRAPE-1 (PROgrammable GRAPE-1), a programmablemulti-purpose computer for many-body simulations. The main difference betweenPROGRAPE-1 and "traditional" GRAPE systems is that the former uses FPGA (FieldProgrammable Gate Array) chips as the processing elements, while the latterrely on the hardwired pipeline processor specialized to gravitationalinteractions. Since the logic implemented in FPGA chips can be reconfigured, wecan use PROGRAPE-1 to calculate not only gravitational interactions but alsoother forms of interactions such as van der Waals force, hydrodynamicalinteractions in SPH calculation and so on. PROGRAPE-1 comprises two AlteraEPF10K100 FPGA chips, each of which contains nominally 100,000 gates. Toevaluate the programmability and performance of PROGRAPE-1, we implemented apipeline for gravitational interaction similar to that of GRAPE-3. One pipelinefitted into a single FPGA chip, which operated at 16 MHz clock. Thus, forgravitational interaction, PROGRAPE-1 provided the speed of 0.96Gflops-equivalent. PROGRAPE will prove to be useful for wide-range ofparticle-based simulations in which the calculation cost of interactions otherthan gravity is high, such as the evaluation of SPH interactions.Comment: 20 pages with 9 figures; submitted to PAS