Faced with several iterations of seemingly stagnant TOP500 releases, there may be some more insight to glean yet thanks to an Exascalar analysis, undertaken by Intel’s Director of Power Technology Execution Winston Saunders.
According to Saunders, “Exascalar is one of the best ways to visualize changes in the Green500 and Top500 lists since it compares both the performance and efficiency of systems in one common analysis.”
Exascalar refers to the “logarithmic distance” to exascale performance (10^18 flops) in a 20 megawatt power envelope. The analysis synthesizes information from both the TOP500 and Green500 rankings, creating a visualization of the primary dependency of performance leadership on efficiency leadership.
Writes Saunders: “In this case the analysis is especially revealing: while the #1 supercomputer in the Top500 has not changed in the last four publications of the lists, the population of the Top500 list has been far from stagnant. This is best revealed by looking at a “comprehenive” set of KPI’s [key performance indicators] for the population.”
The graph below compares the Exascalar plots of November 2014 with that of June 2014. Note that the points from November are smaller red dots, the points with empty blue circles are from June, and red points outlined by blue indicate systems that are on both lists.
Even though the highest performance computer, China’s Tianhe-2, is the same, the overall efficiency changes are clear.
Median Exascalar values are improving, to wit:
November 2014 list, new entrants: -3.63
November 2014 list, all computers -3.99
April 2014 list, all computers: -4.13