Multicore processors and a variety of accelerators have allowed scientific applications to scale to larger problem sizes. We present a performance, design methodology, platform, and architectural comparison of several application accelerators executing a Quantum Monte Carlo application. We compare the application's performance and programmability on a variety of platforms including CUDA with Nvidia GPUs, Brook+ with ATI graphics accelerators, OpenCL running on both multicore and graphics processors, C++ running on multicore processors, and a VHDL implementation running on a Xilinx FPGA. We show that OpenCL provides application portability between multicore processors and GPUs, but may incur a performance cost. Furthermore, we illustrate that graphics accelerators can make simulations involving large numbers of particles feasible.

Recent advances in FPGA technology make them an attractive platform for accelerating scientific computing applications. We present a novel hardware accelerator for Quantum Monte Carlo simulations in N-body systems. The design is deeply pipelined and exploits the inherent fine-grained parallelism available using an FPGA for all calculations. The design is implemented on a Xilinx Virtex II Pro XC2VP30 device and preliminary results indicate a maximum operating frequency of 100MHz. A single instance of our design offers an estimated speedup of 20x and accuracy comparable to the serial code running on a 2.8GHz Intel Pentium 4 processor. This architecture performs all computations with fixed-point representation and delivers accuracy on the order of or better than double-precision floating point. After deploying a single instance on the present FPGA platform, targeting our design on the Cray XD1 platform with a high gate-density FPGA will allow us to operate multiple cores in parallel.