May 10, 2013 
Exascale computing can help solve energy and environmental problems
RICHLAND, Wash. - PNNL's Sriram Krishnamoorthy is one of many scientists reaching for the next step in supercomputer evolution, the exascale computer. D.O.E. has awarded him $2.5 million over 5 years to explore ways to advance exascale computing through their Early Career Research Plan.
The top supercomputers nowadays work at the petascale level, performing in one hour what would take a typical laptop in excess of roughly 20 years to do. But as computer programs that help solve energy and environmental problems get more useful, they also get much bigger. Exascale computing looks for to solve problems that are about one thousand times bigger than what the top computers can do today.
That magnitude requires supercomputers to perform different parts of calculations simultaneously, sometimes on different kinds of computer hardware, and then put all the pieces back together on the fly. This computational style is called parallel computing and its complexity creates challenges such as making sure all the parts of the system are working as well as they can be. In addition, complex, multi-component calculations have more chances to err and crash. Krishnamoorthy has been studying ways to make computers better deal with these issues.
Currently, computational scientists must translate equations that work on conventional machines into computer language and a style that can be used by a parallel computer. Krishnamoorthy has begun to automate parts of this process. He has also created a set of tools that allows programmers to write code in modules that can be automatically matched to different computing platforms, making it easier to customize programs to different systems.
He has also improved how supercomputers handle errors that could make them crash. When a fault crops up, supercomputers return to the last good checkpoint. By creating programs that identify just the work lost due to a fault and only redo that portion, Krishnamoorthy has narrowed the amount of work that a supercomputer has to repeat. This can greatly enhance the speed of science on supercomputers.
He will be using the new support from D.O.E. to delve deeper into how parallel computing solves problems and making sure that the different pieces of the full calculation are working as efficiently as possible. After understanding when and where certain approaches work best in different programs and platforms, he will be testing how they will perform on the computer systems of the future.
Tags: Computational Science, Awards and Recognizes
Interdisciplinary teams at Pacific Northwest National Lab address many of America's most pressing issues in energy, the environment and national security through advances in basic and applied science. PNNL employs 4,500 staff, has an yearly budget of nearly $1 billion, and has been managed for the D.O.E. by Ohio-based Battelle since the laboratory's inception in 1965. For more information, visit the PNNL News Center, or follow PNNL on Facebook, LinkedIn and Twitter.
