Efficiency

IBM T.J. Watson Research Center will develop a two-pronged approach to improve future datacenter efficiency.. New optical interconnect solutions can provide a path to energy-efficient datacenters at higher bandwidth levels, but they must also meet key metrics including power density, cost, latency, reliability, and signal integrity. IBM's team will use their expertise with vertical-cavity surface-emitting lasers (VCSELs) to develop VCSEL-based optical interconnect technology capable of meeting the necessary future demands.

The University of California, Berkeley (UC Berkeley) will develop a new datacenter network topology that will leverage the energy efficiency and bandwidth density through the integration of silicon photonics into micro electro-mechanical system (MEMS) switches. Today's datacenter architectures use server nodes (with processor and memory) connected via a hierarchical network. In order to access a remote memory in these architectures, a processor must access the network to get to a particular server node, gaining access to the local memory of that server.

The University of California, Santa Barbara (UCSB) will develop and demonstrate a technology platform that integrates efficient photonic interfaces directly into chip "packages." The simultaneous design and packaging of photonics with electronics will enable higher bandwidth network switches that are much more energy efficient. Traditional electronic switches toggle connections between wires, each wire providing a different communication channel.

The University of California, San Diego (UC San Diego) will develop a new datacenter network based on photonic technology that can double the energy efficiency of a datacenter. Their LEED project mirrors the development of CPU processors in PCs. Previous limitations in the clock rate of computer processors forced designers to adopt parallel methods of processing information and to incorporate multiple cores within a single chip. The team envisions a similar development within datacenters, where the advent of parallel lightwave networks can act as a bridge to more efficient datacenters.

The Massachusetts Institute of Technology (MIT) will develop a unified optical communication technology for use in datacenter optical interconnects. Compared to existing interconnect solutions, the proposed approach exhibits high energy efficiency and large bandwidth density, as well as a low-cost packaging design. Specifically, the team aims to develop novel photonic material, device, and heterogeneously integrated interconnection technologies that are scalable across chip-, board-, and rack-interconnect hierarchy levels.

Columbia University will develop a new datacenter architecture co-designed with state-of-the-art silicon photonic technologies to reduce system-wide energy consumption. The team’s approach will improve data movement between processor/memory and will optimize resource allocation throughout the network to minimize idle times and wasted energy. Data transfer in datacenters occurs over a series of interconnects that link different server racks of the datacenter together. Networks in modern mega-scale datacenters are becoming increasingly complicated.

Ayar Labs will develop new intra-rack configurations using silicon-based photonic (optical) transceivers, optical devices that transmit and receive information. The team will additionally develop methods to package their photonic transceiver with an electronic processor chip. Marrying these two components will reduce the size and cost of the chip system. Integrated packaging also moves the photonics closer to the chip, which increases energy efficiency by reducing the amount of "hops" between components.

The IBM T.J. Watson Research Center will develop datacenter networking technology incorporating extremely fast switching devices that operate on the nanosecond scale. At the heart of the process is the development of a new type of photonic switch. The dominant switching technology today are electronic switches that toggle connections between two wires, each wire providing a different communication channel. A photonic switch toggles connections between two optical fibers, where each individual fiber themselves can carry many communication channels allowing immense numbers of data transfers.

The University of Southern California (USC) will develop a framework and testbed for evaluating proposed photonic and optical-electronic interconnect technologies, such as those developed under the ARPA-E ENLITENED program. These new approaches will develop novel network topologies enabled by integrated photonics technologies, which use light instead of electricity to transmit information. USC’s effort aims to offer an impartial assessment of these emerging datacenter concepts and architectures and their ability to reduce overall power consumption in a meaningful way.

The United Technologies Research Center (UTRC) will develop an AI-accelerated search technique, LENS, to quickly discover new design concepts for energy applications. The project will combine the strengths of the two pillars of AI—logical inference and statistical learning—to achieve this task by using constraint programming, generative models, reduced order models, active learning, and rule discovery. The end goal is to accelerate the design of power converters, which have a significant impact on energy savings.