Scaling Soft Processor Systems

As FPGA-based systems including soft-processors become increasingly common they are motivated to better understand the best way to scale the performance of such systems. This paper explores the organization of processors and caches connected to a single off-chip memory channel, for workloads composed of many independent threads. In particular they design and evaluate real FPGA-based processor, multithreaded processor, and multiprocessor systems on EEMBC benchmarks-investigating different approaches to scaling caches, processors, and thread contexts to maximize throughput while minimizing area. The main finding is that while a single multithreaded processor offers improved performance over a single-threaded processor, multiprocessors composed of single-threaded processors scale better than those composed of multithreaded processors.