Evaluating the SW26010 many-core processor with a micro-benchmark suite for performance optimizations

The inadequate public information of China's SW26010 processor's micro-architecture prevents global researchers from improving application performances on the TaihuLight supercomputer. This study aims to illuminate the uncharted area of SW26010 in order to provide important information for performance optimizations and modeling. First, we developed a micro-benchmark suite, swCandle, to evaluate the key micro-architectural features. The benchmark results revealed some unanticipated findings beyond the publicly available data. For instance, the broadcast mode of register communications has the same latency as the peer-to-peer mode. Second, we applied the roofline model, with the key parameters obtained with swCandle, to identify the key programming challenge of SW26010. Third, based on the micro-benchmark results and the roofline model analysis, we proposed a systematic guideline for performance optimizations on SW26010 and instantiated the guideline with two cases. The methodology we developed in this study, that infers a processor's micro-architecture design from micro-benchmark results, can also be applied on other processors lacking of public information.