• A Hybrid Conference – In-Person and Virtual Presentations
  • Technical Conference:  05 – 09 March 2023
  • Exhibition: 07 – 09 March 2023
  • San Diego Convention Center, San Diego, California, USA

Slow and Wide Versus Fast and Narrow: How Do We Make our Datacenters Green?


Trey Greer, NVIDIA, USA
Norm Swenson, Norman Swenson Consulting, USA
Xian Zhou, University of Science & Technology Beijing, China
Di Che, Nokia Bell Labs, USA


There are different approaches to improve energy efficiency in and between datacenters. We can continue to press toward higher baud rates and higher bits per symbol, or we can make use of multiplexing techniques over optical wavelength, subcarrier frequency, and spatial/fiber cores at lower baud rates. Which approach results in the best efficiency in terms of overall power consumption for the end-to-end system? This should include power consumption of electrical interconnect, light generation, detection, amplification, signal processing, SERDES and FEC. This workshop will address this topic in two sessions, within the datacenter (chip to chip) and between datacenters.

Short Reach,  <100 meters

The first session will deal with short reach interconnect within a rack or between racks.  Energy per bit is extremely important in these short optical interconnects.  

  • In the context of the bandwidth needed for 100 Tbps switches, where is the sweet spot in the battle between high channel bit rates vs. high fiber counts and channels per fiber? 
  • In lieu of higher channel data rates, what’s the best way to increase the number of channels per fiber core or the number of fiber cores around the host ASIC?
  • On the host ASIC side, can we save power with the wider and slower electrical interfaces made possible with co-packaged optics? 

Long Reach, up to 10km

The second session will look at communications between datacenters.

  • Which technologies and multiplexing techniques promise the most energy efficiency to achieve these distances? Is it intensity modulation/direct detection on multiple lanes, coherent subcarrier multiplexing, simplified coherent, or something else?
  • What’s the role of DSP in a power-efficient transponder? Does DSP actually result in net power savings?
  • What key technologies need to be demonstrated to realize these energy efficient techniques in practical product offerings?



Keren Bergmen, Columbia University, USA

Arash Farhood, Marvell, USA

Joe Kahn, Stanford University, USA

Dan Kuchta, IBM, USA

Di Liang, Alibaba, USA

Karl Muth, Broadcom, USA

Sunil Priyadarshi, Intel, USA

Dave Welch, Infinera, USA