Energy-Efficient Ethernet

Ethernet connections waste lots of watts. It need not be so

3 min read

Ethernet link speeds of 100 megabits per second or even 1 gigabit per second are typical right now in local area networks, but it's very unlikely that you need that much bandwidth all the time. Studies show that on average, people use their Ethernet links at full throttle less than 5 percent of the time. But the circuitry on the network-interface controller, the chip that connects your computer to the network, is always running at full speed, wasting power. In 2005, all the network-interface controllers in the United States--computers, switches, and routers all have them--burned through 5.3 terawattâ''hours of energy, enough to keep 6 million 100-watt lightbulbs shining all year.

”There's no reason to have a 1â''gigabit link when there's no traffic on it,” says Ken Christensen, computer science and engineering professor at the University of South Florida, in Tampa. Christensen and Bruce Nordman, a researcher at the Lawrence Berkeley National Laboratory, in California, have devised one of two schemes vying to become a standard that if put into practice would save some of the wasted watts. Their seemingly simple solution: adapt the Ethernet link's speed to match a device's needs. If you were checking e-mail, for instance, 100Mb/s would be enough, but the network controller would shift to 1Gb/s when downloading a large file. The researchers described the concept, called Adaptive Link Rate, last month in IEEE Transactions on Computers.

Keep Reading ↓Show less

This article is for IEEE members only. Join IEEE to access our full archive.

Join the world’s largest professional organization devoted to engineering and applied sciences and get access to all of Spectrum’s articles, podcasts, and special reports. Learn more →

If you're already an IEEE member, please sign in to continue reading.

Membership includes:

  • Get unlimited access to IEEE Spectrum content
  • Follow your favorite topics to create a personalized feed of IEEE Spectrum content
  • Save Spectrum articles to read later
  • Network with other technology professionals
  • Establish a professional profile
  • Create a group to share and collaborate on projects
  • Discover IEEE events and activities
  • Join and participate in discussions

An IBM Quantum Computer Will Soon Pass the 1,000-Qubit Mark

The Condor processor is just one quantum-computing advance slated for 2023

4 min read
This photo shows a woman working on a piece of apparatus that is suspended from the ceiling of the laboratory.

A researcher at IBM’s Thomas J. Watson Research Center examines some of the quantum hardware being constructed there.

Connie Zhou/IBM

IBM’s Condor, the world’s first universal quantum computer with more than 1,000 qubits, is set to debut in 2023. The year is also expected to see IBM launch Heron, the first of a new flock of modular quantum processors that the company says may help it produce quantum computers with more than 4,000 qubits by 2025.

This article is part of our special report Top Tech 2023.

While quantum computers can, in theory, quickly find answers to problems that classical computers would take eons to solve, today’s quantum hardware is still short on qubits, limiting its usefulness. Entanglement and other quantum states necessary for quantum computation are infamously fragile, being susceptible to heat and other disturbances, which makes scaling up the number of qubits a huge technical challenge.

Keep Reading ↓Show less