Cutting edge advanced computing hardware (aka big iron) does not stand by itself. These computers are the pinnacle of a myriad of technologies that must be carefully woven together by people to create the computational capabilities that are used to deliver insights into the behaviors of complex systems. This collection of technologies and people has been called the High Performance Computing (HPC) ecosystem. This is an appropriate metaphor because it evokes the complicated nature of the interdependent elements needed to deliver first of a kind computing systems.

The idea of the HPC ecosystem has been around for years and most recently appeared in one of the objectives for the National Strategic Computing Initiative (NSCI). The 4^th objective calls for “Increasing the capacity and capability of an enduring national HPC ecosystem.” This leads to the questions of, “what makes up the HPC ecosystem” and why is it so important? Perhaps the more important question is, why does the United States need to be careful about letting its HPC ecosystem diminish?

The heart of the HPC ecosystem is clearly the “big humming boxes” that contain the advanced computing hardware. The rows upon rows of cabinets are the focal point of the electronic components, operating software, and application programs that provide the capabilities that produce the results used to create new scientific and engineering insights that are the real purpose of the HPC ecosystem. However, it is misleading to think that any one computer at any one time is sufficient to make up an ecosystem. Rather, the HPC ecosystem requires a continuous pipeline of computer hardware and software. It is that continuous flow of developing technologies that keeps HPC progressing on the cutting edge.

The hardware element of the pipeline includes systems and components that are under development, but are not currently available. This includes the basic research that will create the scientific discoveries that enable new approaches to computer designs. The ongoing demand for “cutting edge” systems is important to keep system and component designers pushing the performance envelope. The pipeline also includes the currently installed highest performance systems. These are the systems that are being tested and optimized. Every time a system like this is installed, technology surprises are found that must be identified and accommodated. The hardware pipeline also includes systems on the trailing edge. At this point, the computer hardware is quite stable and allows a focus on developing and optimizing modeling and simulation applications.

One of the greatest challenges of maintaining the HPC ecosystem is recognizing that there are significant financial commitments needed to keep the pipeline filled. There are many examples of organizations that believed that buying a single big computer would make them part of the ecosystem. In those cases, they were right, but only temporarily. Being part of the HPC ecosystem requires being committed to buying the next cutting-edge system based on the lessons learned from the last system.

Another critical element of the HPC ecosystem is software. This generally falls into two categories – software needed to operate the computer (also called middleware or the “stack”) and software that provides insights into end user questions (called applications). Middleware plays the critical role of managing the operations of the hardware systems and enabling the execution of applications software. Middleware includes computer operating systems, file systems and network controllers. This type of software also includes compilers that translate application programs into the machine language that will be executed on hardware. There are quite a number of other pieces of middleware software that include libraries of commonly needed functions, programming tools, performance monitors, and debuggers.

Applications software span a wide range and are as varied as the problems users want to address through computation. Some applications are quick “throwaway” (prototype) attempts to explore potential ways in which computers may be used to address a problem. Other applications software is written, sometimes with different solution methods, to simulate physical behaviors of complex systems. This software will sometimes last for decades and will be progressively improved. An important aspect of these types of applications is the experimental validation data that provide confidence that the results can be trusted. For this type of applications software, setting up the problem that can include finite element mesh generation, populating that mesh with material properties and launching the execution are important parts of the ecosystem. Other elements of usability of application software include the computers, software, and displays that allow users to visualize and explore simulation results.

Data is yet another essential element of the HPC ecosystem. Data is the lifeblood in the circulatory system that flows through the system to keep it doing useful things. The HPC ecosystem includes systems that hold and move data from one element to another. Hardware aspects of the data system include memory, storage devices, and networking. Also software device drivers and file systems are needed to keep track of the data. With the growing trend to add machine learning and artificial intelligence to the HPC ecosystem, its ability to process and productively use data are becoming increasingly significant.

Finally, and most importantly, trained and highly skilled people are an essential part of the HPC ecosystem. Just like computing systems, these people make up a “pipeline” that starts in elementary school and continues through undergraduate and then advanced degrees. Attracting and educating these people in computing technologies is critical. Another important part of the people pipeline of the HPC ecosystem are the jobs offered by academia, national labs, government, and industry. These professional experiences provide the opportunities needed to practice and hone HPC skills.

The origins of the United States’ HPC ecosystem dates back to the decision by the U.S. Army Research Lab to procure an electronic computer to calculate ballistic tables for its artillery during World War II (i.e. ENIAC). That event led to finding and training the people, who in many cases were women, to program and operate the computer. The ENIAC was just the start of the nation’s significant investment in hardware, middleware software, and applications. However, just because the United States was the first does not mean that it was alone. Europe and Japan also have robust HPC ecosystems for years and most recently China has determinedly set out to create one of their own.

The United States and other countries made the necessary investments in their HPC ecosystems because they understood the strategic advantages that staying at the cutting edge of computing provides. These well-document advantages apply to many areas that include: national security, discovery science, economic competitiveness, energy security and curing diseases.

The challenge of maintaining the HPC ecosystem is that, just like a natural ecosystem, the HPC version can be threatened by becoming too narrow and lacking diversity. This applies to the hardware, middleware, and applications software. Betting on just a few types of technologies can be disastrous if one approach fails. Diversity also means having and using a healthy range of systems that covers the highest performance cutting edge systems to wide deployment of mid and low-end production systems. Another aspect of diversity is the range of applications that can productively use on advanced computing resources.

Perhaps the greatest challenge to an ecosystem is complacency and assuming that it, and the necessary people, will always be there. This can take the form of an attitude that it is good enough to become a HPC technology follower and acceptable to purchase HPC systems and services from other nations. Once a HPC ecosystem has been lost, it is not clear if it can be regained. Having a robust HPC ecosystem can last for decades, through many “half lives” of hardware. A healthy ecosystem allows puts countries in a leadership position and this means the ability to influence HPC technologies in ways that best serve their strategic goals. Happily, the 4^th NSCI objective signals that the United States understands these challenges and the importance of maintaining a healthy HPC ecosystem.

About the Author

Alex Larzelere is a senior fellow at the U.S. Council on Competitiveness, the president of Larzelere & Associates Consulting and HPCwire’s policy editor. He is currently a technologist, speaker and author on a number of disruptive technologies that include: advanced modeling and simulation; high performance computing; artificial intelligence; the Internet of Things; and additive manufacturing. Alex’s career has included time in federal service (working closely with DOE national labs), private industry, and as founder of a small business. Throughout that time, he led programs that implemented the use of cutting edge advanced computing technologies to enable high resolution, multi-physics simulations of complex physical systems. Alex is the author of “Delivering Insight: The History of the Accelerated Strategic Computing Initiative (ASCI).”