2. nci.org.au
What ACCESS-Opt is
• 3 year effort to “scale-up” and optimize ACCESS-
related work on NCI infrastructure
ACCESS – Australian Community Climate and Earth System Simulator
• Endeavour resourced by 3 partners
• NCI (3 FTEs)
• Bureau of Meteorology (BoM) (3 FTEs)
• Fujitsu (1 FTE)
3. nci.org.au
What ACCESS-Opt is
• Series of work plans with specific
technical & scientific outcomes.
Eg.
• Ultra high resolution global ocean model
• High resolution coupled climate model
• New data assimilation procedures &
workflows
4. nci.org.au
Project Objectives
1. Determine and address scalability, performance
and workflow issues primarily.
1. Assist NCI and BoM in future HPC procurements
with relevant application performance data
1. Contribute to model development with a
performance-oriented focus
5. nci.org.au
Current Work Focus Points
2014-15
• Gather set of applications & configurations for investigation
• Establish testing methodology and software suite
• Profiling and optimization of gathered applications
2015-16
• Construct & profile next-gen configurations of applications
• Higher resolution, new workflows, etc
2016+
• Testing on next generation HPC architectures
• Report on workflow & scalability issues for further generation weather and climate
applications
6. nci.org.au
Methodology
• Thorough understanding of test
platforms
– Raijin, Fujin
• Collect performance gathering tools
– ScoreP, Vampir, PAPI, HPC Toolkit
• Gather benchmark cases and data
• Perform scaling tests
• Analysis of profiles and traces
• Optimization
• Re-analysis
7. nci.org.au
Current areas of work
Unified Model
•Adding new parallel I/O functionality
•Moving 25km to 17km horizontal resolution
•Ultra high-res 1.5 km city domains
•OpenMP parallelization
Modular Ocean Model
•Moving from 0.25o to 0.1o horizontal resolution
•Efficient coupling to Los Alamos sea ice model (CICE)
•Biogeochemical modeling at 0.1o horizontal resolution
•Parallelization of GFDL sea ice model (SIS)
Coupled Climate Modeling
•Parallel IO functionality in ACCESS-CM (UM + MOM + CICE + OASIS3-MCT)
•Profiling of GC-2 (UM + NEMO + CICE + OASIS3)
8. nci.org.au
Current areas of work
4DVAR
• Investigating OS jitter / hyperthreading issues
• Profiling at N320L70 resolution
• Introducing OpenMP parallelization
Ensemble Kalman Filter code
• Test/profile with high-res ocean output
• Rewrite workflow for DA process
9. nci.org.au
Deliverables to date
1. Modular Ocean Model ported to FX10
architecture
2. 0.1o global ocean configuration running
3. MPI-I/O implementation in UM nearly complete
4. 3 papers to be delivered at ISESS 2015
