  The world of computing is in rapid transition, now dominated by a world of
smartphones and cloud services, with profound implications for the future of
advanced scientific computing. Simply put, high-performance computing (HPC) is
at an important inflection point. For the last 60 years, the world's fastest
supercomputers were almost exclusively produced in the United States on behalf
of scientific research in the national laboratories. Change is now in the wind.
While costs now stretch the limits of U.S. government funding for advanced
computing, Japan and China are now leaders in the bespoke HPC systems funded by
government mandates. Meanwhile, the global semiconductor shortage and political
battles surrounding fabrication facilities affect everyone. However, another,
perhaps even deeper, fundamental change has occurred. The major cloud vendors
have invested in global networks of massive scale systems that dwarf today's
HPC systems. Driven by the computing demands of AI, these cloud systems are
increasingly built using custom semiconductors, reducing the financial leverage
of traditional computing vendors. These cloud systems are now breaking barriers
in game playing and computer vision, reshaping how we think about the nature of
scientific computation. Building the next generation of leading edge HPC
systems will require rethinking many fundamentals and historical approaches by
embracing end-to-end co-design; custom hardware configurations and packaging;
large-scale prototyping, as was common thirty years ago; and collaborative
partnerships with the dominant computing ecosystem companies, smartphone, and
cloud computing vendors.
