Superconducting Technology Assessment - nitrd

RSFQ TECHNOLOGY IS VIABLE
Technical Advantages
The most advanced alternative technology.
Combines high speed with low power.
Ready for aggressive investment.
TABLE E-2. RSFQ SUMMARY
Most Advanced Alternative Technology
The ITRS 2004 update on Emerging Research Devices lists many candidate technologies, presently in the research
laboratories, for extending performance beyond today’s semiconductor technology. Superconducting RSFQ is
included in this list and is assessed to be at the most advanced state of any of the alternative technologies.
Ready for Aggressive Investment
In the opinion of the panel, superconducting RSFQ circuit technology is ready for an aggressive, focused investment
to meet a 2010 schedule for initiating the development of a petaflops-class computer. This judgment is based on:
■ An evaluation of progress made in the last decade.
Technical Challenges
Providing high-speed and low-latency memory.
Architecting systems that can tolerate significant
memory access latencies.
■ Projection of the benefits of an advanced very-large-scale integration (VLSI) process
for RSFQ in a manufacturing environment.
■ A roadmap for RSFQ circuit development coordinated with VLSI manufacturing
and packaging technologies.
Providing very high data rate communications between
room temperature technology and cooled RSFQ.
Can Leverage Semiconductor Technology Base
Although RSFQ circuits are still relatively immature, their similarity in function, design, and fabrication to semiconductor
circuits permits realistic extrapolations. Most of the tools for design, test, and fabrication are derived directly from
the semiconductor industry, although RSFQ technology will still need to modify them. Significant progress has
already been demonstrated on limited budgets by companies such as Northrop Grumman and HYPRES, and in
universities such as Stony Brook and the University of California, Berkeley.
High Speed with Low Power
Individual RSFQ circuits have been demonstrated operating at clock rates in the hundreds of GHz, and system
clocks of at least 50GHz seem quite attainable, with faster speeds possible. In addition, RSFQ devices have lower
power requirements than other systems, even after cooling requirements are included. Extremely low RSFQ power
enables compact systems with greatly increased computational capability for future government needs, but with
no increase in overall power requirements beyond today’s high-end systems.
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