I am a member of the U.S. National Academies Board on Global Science and Technology (BGST). As the name suggests, the role of BGST is to examine the shifting nature of the global science and technology enterprise and its implications. These include the global flow of intellectual talent and capital, the interplay of government policies, research and development priorities, innovation and technology transfer, and global competitiveness and security. This is a wide-ranging mandate, which is both exciting and challenging.
As a member of BGST, I recently chaired a study, commissioned by the U.S. Department of Defense, on the issues surrounding the end of Dennard scaling and its implications for U.S. industry, defense capabilities and national security. The report, The New Global Ecosystem in Advanced Computing: Implications for U.S. Competitiveness and National Security, was just released. It is a cautionary tale about the Gordian knot of intellectual and economic interdependencies, of epochal ecosystem shifts, and the global consequences of both.
Lest this seem mere academic punditry, remember that 30-40 percent of U.S. net economic growth in recent decades has been due to advances in information technology. This is not just a tale of Silicon Valley, but also one for the entire country's economy.
Beyond Dennard Scaling
Moore's Law, the notion that the number of transistors in a given silicon area doubles roughly every two years, is not a law or even a theorem. Rather, it was an empirical observation, originally made by Gordon Moore in 1965. For over forty years, it has continued to hold true by virtue of enormous intellectual effort, ongoing architectural and software innovation, and billions of dollars of investments in process technology and silicon foundries. In turn, consumers, businesses and governments have been the happy beneficiaries of faster microprocessors, more powerful, inexpensive and ubiquitous computing devices and a rich and varied suite of software applications.
However, there is bad news. The continued and seemingly miraculous improvement in general processor performance is now over, a consequence of physical limits on transistor shrinkage that was itself a happy consequent of Dennard scaling. To be clear, Moore's law continues, with the number of transistors on a chip continuing to double, but the transistors no longer become more energy efficient as they shrink. The result has been bounds on microprocessor clock rates due to energy dissipation constraints and the concomitant rise of multicore chips and function-specific accelerators such as GPUs. (See Battling Evil: Dark Silicon and Nothing Is Forever for a few reflections and details.)
This radical shift breaks a virtuous cycle of mutually reinforcing benefits, one where software developers created feature-filled applications and stimulated demand for faster general-purpose processors, which then drove the creation of even more advanced applications. Simply put, we are the reluctant, wide-eyed denizens of a brave new world, one where the cherished and popular expectation that applications would run faster without change each time a new backward-compatible processor appeared.
There is a technical way forward, but it means embracing application parallelism and retargeting software to each new generation of non-compatible, heterogeneous multicore processors. As over fifty years of research in parallel computing has shown, this is a path fraught with pain and difficulty. In turn, this has profound implications for the future of the silicon ecosystem and the nature and locus of continued innovation. It is the trillion-dollar inflection point, pivoting on chip performance, business models and global markets.
The end of Dennard scaling and the emergence of heterogeneous multicore processors has coincided with another shift, the transition from an era dominated by PCs to one defined by smartphones and tablets. For much of the world, the smartphone is now the primary computing system, and in developing economies, the aspirational feature phone is the only computing device. More to the point, the majority of PC and smartphone users are not in the U.S., nor will they ever be again. Not surprisingly, these two phenomena, the end of Dennard scaling and the rise of smartphones and tablets are deeply interrelated.
The PC ecosystem has long been driven by the phenomenal success of the x86 microprocessor family and successive generations of processors from Intel and AMD, both U.S. companies. Conversely, the smartphone and tablet ecosystem is largely based on the ARM microprocessor family and low power systems-on-a-chip (SoCs) developed by ARM licensees around the world. Beyond the ongoing competition between PC and smartphone vendors, this is a battle of business models, pitting a closed x86 ecosystem with captive silicon foundries against fabless semiconductor design firms that mix and match function-specific accelerators with ARM cores and use Taiwan Semiconductor Manufacturing Company (TSMC) as a foundry.
Enormous resources are being invested in both silicon ecosystems, with x86 designers seeking to "grow down" by reducing power and integrating functionality on chip to compete in the smartphone and tablet market. Conversely, ARM designers are seeking to "grow up" by increasing performance and adding features to compete with x86 designs in the server market. This battle royal is not winner take all. Rather, it is a competition to define the global nexus of innovation, with profound implications for global IT dominance in the next decade.
Global Competitiveness and BGST
It is with this backdrop that the BGST committee examined the technical consequences from the end of Dennard scaling, the cultural and economic challenges of parallelism, the possible shifts of capital and talent, and national and regional investments in IT research. The report's broad conclusions include the following: (a) the U.S. still leads in basic IT research, but the global gap continues to shrink, (b) IT investment strategies and challenges differ markedly across countries and regions, (c) single chip performance is unlikely to continue as the predominate focus of innovation, (d) there are serious risks that growing international markets will diminish U.S. influence and (e) U.S. national security and defense readiness depends on continued rapid uptake and deployment of advanced IT.
I encourage you to download and read the complete BGST report for additional details and insights.
In IT and innovation circles, Gordon Moore is also famous for another dictum, "only the paranoid survive." What he really said is more nuanced and relevant to the global innovation competition, "Success breeds complacency. Complacency breeds failure. Only the paranoid survive." It is worth pondering as one considers the interplay of science and technology, economics, government policy, and business models.
I would be remiss if I did not express my sincere thanks to the members of the BGST report committee: Cong Gao (Nottingham), Tai Ming Cheung (UCSD), John Crawford (Intel), Dieter Ernst (East-West Center), Mark Hill (Wisconsin), Steve Keckler (NVidia), David Liddle (U.S. Venture Partners), and Kathryn McKinley (Microsoft). There were thoughtful, dedicated and indefatigable. Finally, all of the committee members are deeply indebted to Bill Berry, Ethan Chiang and Lynette Millett from the National Academies.