June 22–26, 2014
Leipzig, Germany

Presentation Details

Name: Challenges of Getting ECMWF's Weather Forecast Model (IFS) to the Exascale
Time: Wednesday, June 25, 2014
11:30 am - 12:00 pm
Room:   Hall 5
CCL - Congress Center Leipzig
Breaks:10:30 am - 11:30 am Coffee Break
Speaker:   George Mozdzynski, ECMWF
Abstract:   ECMWF is a partner in the Collaborative Research into Exascale Systemware, Tools and Applications (CRESTA) project, funded by a EU call for projects in Exascale computing, software and simulation (ICT-2011.9.13).  The significance of the research carried out within the CRESTA project is that it will demonstrate techniques required to scale the current generation of Petascale capable simulation codes towards the performance levels required for running on future Exascale systems. Today the European Centre for Medium-Range Weather Forecasts (ECMWF) runs a 16 km global T1279 operational weather forecast model using about 3K cores of an CRAY XC-30 system. Following the historical evolution in resolution upgrades, ECMWF could expect to be running a 2.5 km global forecast model by 2030 on an Exascale system that should be available and hopefully affordable by then. To achieve this would require IFS to run efficiently on about 1000 times the number of cores it uses today. This is a significant challenge, one that we are addressing within the CRESTA project. At the start of the CRESTA project the highest core count that an IFS model used was 10K. Today this number is 220K. Of course, getting to millions of cores remains a formidable challenge. Within CRESTA, ECMWF has explored the use of Fortran2008 coarrays, the details being outlined in this talk. This work and other planned developments should allow an IFS model to utilise an Exascale sized system in the 2030 time-frame.