I might as well copy-paste the main summary of the June 2014 Top500 list, as the November list says much the same thing. There’s almost no change in the top 10, little performance growth compared to The Way It Was™, and the #500 position on the current list was #421 in the previous list. That may sound decent in abstract, but that’s the lowest turnover rate they’ve ever had. Looking at the performance development over time you can see a clear slowdown in recent years. The Chinese Tianhe-2 has been top dog for the past two years, but it’s normal for the peak system to last a while, as can be seen in the staircase pattern of the #1 line in the image below.
There is some stuff coming down the pipe that should make performance perk up a little bit, such as Intel’s Knights Hill coprocessors or nVidia’s Volta GPUs, which are already slated for some soon-to-be-built systems. I still don’t know whether the recent slowdown is fundamentally limited by economics or technological innovation though. Human appetite for operations per second doesn’t appear to have any near-term limits (I could certainly use more). Perhaps the more amazing thing is that previous growth was so steady for so long.