Kilometer-Level Coupled Modeling Using 40 Million Cores: An Eight-Year Journey of Model Development
<|reference_start|>Kilometer-Level Coupled Modeling Using 40 Million Cores: An Eight-Year Journey of Model Development: With current and future leading systems adopting heterogeneous architectures, adapting existing models for heterogeneous supercomputers is of urgent need for improving model resolution and reducing modeling uncertainty. This paper presents our three-week effort on porting a complex earth system model, CESM 2.2, to a 40-million-core Sunway supercomputer. Taking a non-intrusive approach that tries to minimizes manual code modifications, our project tries to achieve both improvement of performance and consistency of the model code. By using a hierarchical grid system and an OpenMP-based offloading toolkit, our porting and parallelization effort covers over 80% of the code, and achieves a simulation speed of 340 SDPD (simulated days per day) for 5-km atmosphere, 265 SDPD for 3-km ocean, and 222 SDPD for a coupled model, thus making multi-year or even multi-decadal experiments at such high resolution possible.<|reference_end|>
@article{duan2024kilometer-level,
    title={Kilometer-Level Coupled Modeling Using 40 Million Cores: An Eight-Year
  Journey of Model Development},
    author={Xiaohui Duan, Yuxuan Li, Zhao Liu, Bin Yang, Juepeng Zheng, Haohuan
  Fu, Shaoqing Zhang, Shiming Xu, Yang Gao, Wei Xue, Di Wei, Xiaojing Lv,
  Lifeng Yan, Haopeng Huang, Haitian Lu, Lingfeng Wan, Haoran Lin, Qixin Chang,
  Chenlin Li, Quanjie He, Zeyu Song, Xuantong Wang, Yangyang Yu, Xilong Fan,
  Zhaopeng Qu, Yankun Xu, Xiuwen Guo, Yunlong Fei, Zhaoying Wang, Mingkui Li,
  Yingjing Jiang, Lv Lu, Liang Su, Jiayu Fu, Peinan Yu, Weiguo Liu, Lixin Wu,
  Lanning Wang, Xin Liu, Dexun Chen and Guangwen Yang},
    journal={arXiv preprint arXiv:2404.10253},
    year={2024},
    archivePrefix={arXiv},
    eprint={2404.10253},
    primaryClass={cs.DC}
}