Synopsis

While the #1 performing supercomputer in the Top500 has not changed in the last five publications of the Top500 list (since Jun 2013), the population of the top supercomputers has been far from stagnant. The computer at the top of the efficiency mark, the #1 Green500 computer has changed with every publication.

Exascalar explores the full richness of the Top500 and Green500 supercomputers using intuitive “data visuaization” techiques. By seeing how and where changes occur, we can gain deeper insight into trends which are helpful in understanding what lies ahead.

This analysis contains the usual Exasclat plot, showing change between the June 2015 lists and the Novmber2014 lists. It also contains compares the Top Exascalar systems and looks at the role of core counts and GPU’s.

Background and notes

Supercomputer leadership requires both extreme scale and high efficiency. The Green500 and Top500 lists are excellent resources for understanding this. But they are both, well, lists, which makes it hard to recognize trends and correlations. The approach here is to leverage data visualization techniques to explore some of the richness of the combined high quality data contained in both lists. While the Top500 emphasizes highest performance, and the Gree500 emphasizes the highest efficiency, Exascalar analysis is conceived as a way to visualize supercomputer efficiency and performance in one coherent picture.

The name Exascalar originates from the goal of achieving an exaflops, \(10^{12}\) mflops, in an envelope of \(20\) MWatt. Exascalar is a logarithmic parametric indicator of progress in efficiency and performance along an iso-power line toward this goal. You can actually Google it.

While source code is made freely available on Github, I welcome suggestions for additional anlayses (or even half-baked experiments) which might be of interest. You can reach me via twitter @WinstonOnEnergy

This analysis is done independently and reflects my opinions alone. In particular, it in no way reflects opinions of my employer (Intel Corporation) or any other entity with which I’m affiliated.

June 2015 Exascalar

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This section focuses on the June 2015 lists and the Exascalar ranking of the data.

Exascalar Plot

The easiest way to visualize change in the Top500 and Green500 lists is to overlay the Exascalar plots of November 2014 with that of June 2015.

In the plot below points from June 2015 are smaller red dots, points with empty blue circles are computers that are no longer on the list, and red points with blue circles around them are computers on both lists. Changes are clearly visible. While the highestperformance computer did not change, changes within the population as well as at the extremes of efficiency are evident.

Reaching back: Comparing June 2015 to June 2013

To emphasize the massive changes in the population of the top supercomputers, it’s instructive to compare not only to the last iteration, but also the last iteration where the #1 Supercomputer changed, two years ago in June 2013. In intervening years the minimum performance needed to make the Top500 has increased over 50%. In addition, the maximum efficiency has increased by about the same magnitude. This neatly emphasizes why the population holds as much (and perhaps more) interest as the top one or two systems.

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