Abstract

As a community we have almost forgotten, what supercomputing was like twenty years ago in 1985. 

The state-of-the-art system then was a 2 Gflop/s peak Cray-2, with at that time a phenomenal 2 GBytes memory. It was the era of custom-built vector mainframes, where anything beyond 100 Mflop/s sustained was considered excellent performance. The software environment was Fortran with vectorizing compilers (at best), and a proprietary operating system. There was hand tuning only, no tools, no visualization, and dumb terminals with remote batch. If one was lucky and had an account, remote access via 9600 baud was state-of-the-art. Usually, a single code developer developed and coded everything from scratch.

What a long way we have come in the last twenty years! Teraflop/s level performance on inexpensive, highly parallel commodity clusters, open source software, community codes, grid access via 10 Gbit/s, powerful visualization systems, and a productive development environment on a desktop system that is more powerful than the Cray-2 from 20 years ago'these are the characteristics of high performance computing in 2005.

Of course, a significant contribution to this progress is due to the continued increase of computing power following Moore's Law. But what I want to argue here is that progress was not just simply quantitative alone. We did not just get more of the same at a cheaper price. There were several powerful ideas and concepts that were shaped in the last 20 years that made supercomputing the vibrant field that it is today.  As an active researcher in the field for the last 25 years, I will offer my subjective opinion, what were the real top breakthrough ideas that led to qualitative change and significant progress in our field?

Retrospection leads to extrapolation: in the last part of the lecture, I will envision what supercomputing will be like 20 years from now in the year 2025.  Can we expect similar performance increases?  How will supercomputing change qualitatively, and what are the top challenges that we will have to overcome to reach that vision of supercomputing in 2025?

Dr. Horst D. Simon
Biographical Sketch

Dr. Horst Simon was named Associate Laboratory Director (ALD) for Computing Sciences at Berkeley Lab in 2004. In his role as the ALD for Computing Sciences, Horst represents the interests of the three computing divisions, NERSC, Computational Research, and Information Technologies and Services, in the formulation of Laboratory policy, and to communicate Laboratory actions on policy and procedures as appropriate. He also coordinates constructive interactions within the computing sciences divisions to seek coupling with other scientific programs.

Horst joined LBNL in early 1996, as director of the newly formed NERSC Division, and was one of the key architects in establishing NERSC at its new location in Berkeley. The NERSC Center is DOE's flagship supercomputing facility for unclassified research funded by DOE's Office of Science and is used by 2,276 users at 312 institutions. Under Horst's leadership, NERSC has enabled important discoveries in fields ranging from global climate modeling to astrophysics. Horst is also the founding director of Berkeley Lab's Computational Research Division, which conducts applied research and development in computer science, computational science, and applied mathematics. His research interests are in the development of sparse matrix algorithms, algorithms for large-scale eigenvalue problems, and domain decomposition algorithms for unstructured domains for parallel processing. His recursive spectral bisection algorithm is regarded as a breakthrough in parallel algorithms for unstructured computations, and his algorithm research efforts were honored with the 1988 Gordon Bell Prize for parallel processing research. Horst was member of the NASA team that developed the NAS Parallel Benchmarks, a widely used standard for evaluating the performance of massively parallel systems. He is also one of four editors of the twice-yearly "TOP500" list of the world's most powerful computing systems.

Video is now online from our most recent CITRIS Distinguished Speaker Series event. View Dr. Horst Simon's prentation:
"Progress in Supercomputing: The Top Three Breakthroughs in the Last 20 Years and the Top Three Challenges for the Next 20 Years"