Optical interconnects for extreme scale computing systems

• Published in: Parallel computing Vol. 64; no. C; pp. 65 - 80
• Main Authors: Rumley, Sébastien, Bahadori, Meisam, Polster, Robert, Hammond, Simon D., Calhoun, David M., Wen, Ke, Rodrigues, Arun, Bergman, Keren
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01.05.2017; Elsevier
• Subjects: Exascale; High performance computing; Interconnection networks; Optical interconnects; Silicon photonics; Optical interconnects; Exascale; Silicon photonics; High performance computing; Interconnection networks
• ISSN: 0167-8191; 1872-7336
• DOI: 10.1016/j.parco.2017.02.001

•Face-to-face comparison of major large scale HPC interconnects.•Review of challenges and solutions for increased use of optics in HPC.•Description of optical switching, in terms of principle, limitations, technical requirements and benefits. Large-scale high performance computing is permeating nearly every corner of modern applications spanning from scientific research and business operations, to medical diagnostics, and national security. All these communities rely on computer systems to process vast volumes of data quickly and efficiently, yet progress toward increased computing power has experienced a slowdown in the last number of years. The sheer cost and scale, stemming from the need for extreme parallelism, are among the reasons behind this stall. In particular, very large-scale, ultra-high bandwidth interconnects, essential for maintaining computation performance, represent an increasing portion of the total cost budget. Photonic systems are often cited as ways to break through the energy-bandwidth limitations of conventional electrical wires toward drastically improving interconnect performance. This paper presents an overview of the challenges associated with large-scale interconnects, and reviews how photonic technologies can contribute to addressing these challenges. We review some important aspects of photonics that should not be underestimated in order to truly reap the benefits of cost and power reduction.