Comparative Analysis of RISC-V Softcore and Hardcore Processors for Space Computing

Selecting a suitable processor architecture is crucial due to the tradeoffs between performance and power consumption for embedded space systems. Interest in the RISC-V processor architecture has quickly risen due to its open-source nature and modular design. In addition, RISC-V softcore processors enable designers to implement RISC-V architecture in a field-programmable gate array (FPGA). Several advantages such as reconfigurability and scalability make FPGAs an appealing option for onboard processing needs for space. With a large selection of both softcore and hardcore processors, evaluating selected platforms becomes challenging and time-consuming for designers. This study evaluates the recently released RISC-V softcore IP, the AMD MicroBlaze V, and compares its performance to other available hardcore and softcore processors. Other soft- and hardcore processors, such as the AMD MicroBlaze, the RISC-V architecture in the Microchip PolarFire SoC and the ARM Cortex-A9 architecture in the AMD Zynq-7020 SoC are considered in this study. Both kernel and synthetic benchmarks, including SpaceBench, CoreMark and Dhrystone, are used to measure the performance and power consumption of each platform. The PolarFire SoC and MicroBlaze V achieve single-core performance results of 3.13 and 2.27 CoreMarks per MHz, respectively. Additionally, under the evaluation of Dhrystone benchmark, the PolarFire SoC and MicroBlaze V achieve scores of 1.40 and 1.88 DMIPS per MHz, respectively. Finally, SpaceBench results present similar performance with minor variations between MicroBlaze V and MicroBlaze.