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DOE Pulse
  • Number 305  |
  • February 15, 2010

Computational science programming model crosses the petaflop barrier

Using Global Arrays, distributed dense arrays can be accessed through a shared memory-like style.

Using Global Arrays, distributed
dense arrays can be accessed
through a shared memory-like
style.

Researchers at DOE's Pacific Northwest National Laboratory and Oak Ridge National Laboratory have demonstrated that the PNNL-developed Global Arrays computational programming model can perform at the petascale level.  The demonstration performed at 1.3 petaflops—or 1.3 quadrillion numerical operations per second—using over 200,000 processors.  This represents about 50% of the processors’ peak theoretical capacity.  Global Arrays is one of only two programming models that has achieved this level of performance.

The Global Arrays technology was used in a computational chemistry simulation that was presented during the annual SuperComputing conference in November. The paper describing the simulation was a finalist for the Gordon-Bell prize that recognizes outstanding achievement in high-performance computing applications.

Global Arrays allows researchers to access data directly from the memory of another node without requiring interaction from the remote processor—the researcher can send or receive data to or from another node with no contact or coordination in advance.

This enables researchers to more efficiently access global data, run bigger models, and simulate larger systems, resulting in a better understanding of the data and processes being evaluated.

For example, the data used in this demonstration focused on water modeling. Water is essential in numerous key chemical and biological processes, and accurate models are critical to understanding, controlling, and predicting the physical and chemical properties of complex aqueous systems.

The computational chemistry simulation performed using Global Arrays provided researchers with more accurate data pertaining to research on the properties of water at the molecular level as well as its interactions with molecules and its behavior at interfaces.

Part of this work was performed at EMSL, a U.S. Department of Energy national scientific user facility at PNNL; using NWChem computational chemistry package.—MaryAnne Wuennecke

Submitted by DOE's Pacific Northwest National Laboratory