Challenges and solutions to improve the scalability of an operational regional meteorological forecasting model Online publication date: Sat, 21-Mar-2015
by Alvaro L. Fazenda, Jairo Panetta, Daniel M. Katsurayama, Luiz F. Rodrigues, Luis F.G. Motta, Philippe O.A. Navaux
International Journal of High Performance Systems Architecture (IJHPSA), Vol. 3, No. 2/3, 2011
Abstract: This work investigates the parallel scalability of BRAMS, a limited area weather forecasting production code, from O(100) cores to O(1,000) cores on large grids (20 km and 10 km resolution runs over South America). Initial experiments show lack of scalability at modest core count. Execution time profiling and source code examination revealed the causes of the limited scalability: sequential algorithms and extensive memory requirements at scarcely used phases of the computation. As processor count increases, these 'secondary' phases dominate execution time. Algorithm replacement and memory reduction generate a new code version that possesses strong and weak scaling. The new version achieved a speed-up of 6 from 100 to 700 processors on the 20 km resolution grid and a speed-up of 6.9 on the same processor range on the 10 km resolution grid. Results were confirmed at another machine with a distinct architecture. Further experiments show that the scalability of the 20 km resolution case is limited by load unbalancing at the most demanding computational phase.
Online publication date: Sat, 21-Mar-2015
If you are not a subscriber and you just want to read the full contents of this article, buy online access here.Complimentary Subscribers, Editors or Members of the Editorial Board of the International Journal of High Performance Systems Architecture (IJHPSA):
Login with your Inderscience username and password:
Want to subscribe?
A subscription gives you complete access to all articles in the current issue, as well as to all articles in the previous three years (where applicable). See our Orders page to subscribe.
If you still need assistance, please email email@example.com