The GPU version of LASG/IAP Climate System Ocean Model version 3 (LICOM3) under the heterogeneous-compute interface for portability (HIP) framework and its large-scale application

Abstract

Abstract. A high-resolution (1/20∘) global ocean general circulation model with graphics processing unit (GPU) code implementations is developed based on the LASG/IAP Climate System Ocean Model version 3 (LICOM3) under a heterogeneous-compute interface for portability (HIP) framework. The dynamic core and physics package of LICOM3 are both ported to the GPU, and three-dimensional parallelization (also partitioned in the vertical direction) is applied. The HIP version of LICOM3 (LICOM3-HIP) is 42 times faster than the same number of CPU cores when 384 AMD GPUs and CPU cores are used. LICOM3-HIP has excellent scalability; it can still obtain a speedup of more than 4 on 9216 GPUs compared to 384 GPUs. In this phase, we successfully performed a test of 1/20∘ LICOM3-HIP using 6550 nodes and 26 200 GPUs, and on a large scale, the model's speed was increased to approximately 2.72 simulated years per day (SYPD). By putting almost all the computation processes inside GPUs, the time cost of data transfer between CPUs and GPUs was reduced, resulting in high performance. Simultaneously, a 14-year spin-up integration following phase 2 of the Ocean Model Intercomparison Project (OMIP-2) protocol of surface forcing was performed, and preliminary results were evaluated. We found that the model results had little difference from the CPU version. Further comparison with observations and lower-resolution LICOM3 results suggests that the 1/20∘ LICOM3-HIP can reproduce the observations and produce many smaller-scale activities, such as submesoscale eddies and frontal-scale structures.

Overestimated Eddy Kinetic Energy in the Eddy‐Rich Regions Simulated by Eddy‐Resolving Global Ocean–Sea Ice Models

“…The spatial distribution of eddies is classified as eddy‐rich and eddy‐poor regions in order for us to trace the biases and to improve the performance of the eddy‐resolving ocean model in the future. Different from the previous studies on OGCMs with higher resolution (e.g., Chassignet & Xu, 2017; Iovino et al., 2016; P. Wang et al., 2021), here we just focus on evaluating the results from the OGCMs of about 0.1° or 10 km, which are and will be the ocean components of the next‐generation climate models for the foreseeable future.…”

Differentiable Programming for Earth System Modeling

“…Rewriting an ESM in a differentiable manner has the potential co-benefit that such a rewrite can also incorporate other modern programming techniques such as GPU usage and the use of low-precision computing, both resulting in potentially huge performance gains (Häfner et al, 2021;Wang et al, 2021;Klöwer et al, 2022). Another more technical challenge is that when computing gradients of functions of trajectories of ESMs over many timesteps, saving all intermediate steps needed to compute the gradient requires a prohibitively large amount of RAM.…”

GPU-HADVPPM V1.0: high-efficient parallel GPU design of the Piecewise Parabolic Method (PPM) for horizontal advection in air quality model (CAMx V6.10)

“…CC BY 4.0 License. Mielikainen et al, 2012b;Mielikainen et al, 2013a ;Mielikainen et al, 2013b;Price et al, 2014;Huang et al, 2015), ocean models such as LASG/IAP Climate System Ocean Model (LICOM; Jiang et al, 2019;Wang et al, 2021a) and Princeton Ocean Model (POM; Xu et al, 2015), and the Earth System Model of Chinese Academy of Sciences (CAS-EMS; Wang et al, 2021b ;Wang et al, 2021c). Govett et al, (2017) used Open Accelerator (OpenACC) directives to port the dynamics of NIM to the GPU and achieved 2.5x acceleration.…”