Matched-resolution performance comparison with Oceananigans

Conduct a like-for-like comparison between the legoESM ocean and the GPU-optimized Oceananigans ocean dynamical core at matched resolution, time step, and hardware to determine their relative computational performance.

Background

The paper reports computational scaling for legoESM’s atmosphere and ocean on CPUs and GPUs, including comparisons with established models and descriptions of communication and domain-decomposition limits. It notes that Oceananigans achieves approximately a decade of near-global ocean simulation per wall-clock day at 8-km resolution on 64 A100 GPUs.

Because the reported Oceananigans and legoESM performance results do not use identical resolution, time step, and hardware configurations, the paper leaves their relative performance unresolved. A controlled comparison under matched conditions is therefore identified as future work.

References

For context, a GPU-optimized hydrostatic ocean dynamical core (Oceananigans) simulates about a decade of near-global ocean per wall-clock day at 8-km resolution on 64 A100 GPUs; a like-for-like comparison with the legoESM ocean, at matched resolution, time step and hardware, is left for future work.

— legoESM: a modular, differentiable, multiscale, AI-ready Earth system model built with AI agents  (2610.11883 - Gentine et al., 8 Oct 2026) in Section “Performance and scalability”