GPU Acceleration of the NEMO Ocean Model (GNEMO)

图形处理器单元（gpu）越来越多地被用作高性能协处理器，为提高应用程序性能的问题提供了成本和节能的解决方案。我们提出了一个为期12个月的项目，将NEMO海洋模型移植到gpu并评估其性能。英国NEMO的三个主要用户，南安普顿国家海洋学中心（NOCS）、普罗德曼海洋学实验室（POL）和英国气象局，正在支持该项目。开发高性能系统的NEMO海洋代码对英国海洋建模界具有重要的战略意义。高性能计算现在正处于一个转折点。在十年的时间里，在合理的成本和功耗预算下实现百亿亿级的性能水平，将需要对硬件进行革命性的改变，并给我们带来巨大的软件挑战。这将包括每个芯片和每个节点的内核数量的大幅增加，系统中执行线程数量的大幅增加（接近1000万），以及每个内核的内存，特别是每个内核的内存带宽的减少。我们已经看到，一些内存密集型应用程序在四核上的运行速度比双核慢。在技术计算中使用图形处理单元（gpu）是一种新兴的体系结构，引起了人们的广泛关注。已公布的WRF天气和气候软件以及其他CFD代码的结果表明，这种代码可以实现可能的加速。我们将为包含GPU处理器的异构系统开发NEMO代码的实现。主要的技术工作将在STFC的Daresbury实验室的计算科学与工程系进行。对基准模拟的gpu实现的评估将由POL、NOCS和Met Office负责。该准则将适用于广泛的深海和大陆架海洋应用，包括气候变化影响、海洋科学、渔业研究和近海工业。代码将被开发成相当于TRL4的软件；包括用全尺寸数据集验证GPU代码。

Graphical Processor Units (GPUs) are being increasingly used as high-performance co-processors, offering cost- and energy-efficient solutions to the problem of enhancing application performance. We propose a 12-month project to port the NEMO Ocean Model to GPUs and to evaluate its performance. Three key users of NEMO in the UK, the National Oceanography Centre, Southampton (NOCS), the Proudman Oceanographic Laboratory (POL) and the UK Meteorological Office, are supporting the project. The NEMO ocean code exploiting high-performance systems has become of great strategic importance for the UK oceanographic modeling community. High-Performance Computing is at a turning point right now. Achieving Exascale performance levels within reasonable cost and power budgets in ten years' time will require revolutionary changes to hardware and present us with substantial software challenges. This will include large increases in the number of cores per chip and per node, massive increases in the number of threads of execution in the system (towards ten million) and reduction in memory per core and especially memory bandwidth per core. We are already seeing this in that some memory-intensive applications are running slower on quad-core than dual-core. An emergent architecture that is attracting much attention is the use of Graphical Processing Units (GPUs) for technical computing. Published results for the WRF weather and climate software and for other CFD codes show the possible speed-up that can be achieved for this kind of code. We shall develop an implementation of the NEMO code for heterogeneous systems containing GPU processors. The major technical work will be carried out in the Computational Science & Engineering Department at STFC's Daresbury Laboratory. Assessment of the GPU-implementation for benchmark simulations will be contributed by POL, NOCS and the Met Office. The code will have application to a wide range of deep ocean and shelf sea applications including climate change impacts, ocean science, fisheries research and offshore industries. The code will be developed to the software equivalent of TRL4; including validation of the GPU code with full-scale datasets.