Benchmarking using the Community Atmospheric Model

The Community Atmospheric Model (CAM) is a global atmosphere model developed for the weather and climate research communities. CAM also serves as the atmospheric component of the Community Climate System Model (CCSM). As a community model, it is important that CAM run efficiently on different architectures, and that it be easily ported to and optimized on new platforms. The current version of CAM contains a number of performance portability features compile-time or runtime parameters that can be used to optimize performance for a given platform, problem or processor count. The large number of tuning options can make benchmarking an arduous task. The paper describes these options and how optimization is managed to make it feasible for evaluation of early systems. The paper also describes some of the performance sensitivities of selected platforms to the different tuning options.