When the Intrepid and Jugene supercomputers earned the top two honors in last month's Graph 500 ranking of the world's best performing supercomputers, researchers from the IU Open Systems Lab (OSL) had good reason to cheer.

For the second straight ranking, an OSL team led by computer science researcher Jeremiah Willcock contributed to a method of measuring these supercomputers' abilities to search and access massive data sets that led to their high ranking.

"The Graph 500 represents an important advancement in the ranking of supercomputers," said OSL Director Andrew Lumsdaine. "Unlike the Linpack benchmark for the Top 500, the Graph 500 focuses not on speed or raw power, but on a supercomputer's ability to access data. For many areas of science, including bioinformatics and medical research, this is the more important metric."

The graph applications measured by the Graph 500 benchmark are also representative of problems occurring in business analytics, data mining, and security.

Both of the two winning entries used more than 131,000 cores and more than 52 terabytes of data; this scale is similar to using 32,000 quad-core laptops. Algorithmic and data compression techniques developed by Willcock were essential to performance at this scale.

The top-ranked Intrepid is an IBM Blue Gene/P supercomputer owned by Argonne National Laboratory near Chicago. The second-ranked Jugene system, also a Blue Gene/P system, is owned by the Jülich Supercomputing Centre in Germany. The software writing team for the Blue Gene/P systems included Jeremiah Willcock and Andrew Lumsdaine from the OSL, along with an IBM team led by Fabrizio Petrini and including Fabio Checconi, Yogish Sabharwal, Anamitra Chodhury, Anshul Mittal and Parul Gupta.

Lumsdaine continued, "Jeremiah and Fabrizio's work has been instrumental in supporting this benchmarking process and in helping systems like Intrepid and Jugene obtain amazing levels of performance. Many experts would not have expected a standard supercomputer to perform well on graph applications compared to more specialized computers."

The Open Systems Lab is part of the Pervasive Technology Institute Digital Science Center at Indiana University.

To view the current Graph 500 List and read more about the search benchmark, visit http://www.graph500.org/.