DEMANDING: Internet traffic volume doubles every three years, yet this increase in usage has not been matched by a similar increase in network energy efficiency, notes researcher Diego Reforgiato Recupero. Image: Courtesy of Gregory Maxwell, via WikiMedia Commons
The Internet may not consume nearly as much environmentally unfriendly fossil fuel as airplanes or automobiles, but the growth of cloud-based services offered by Apple, Netflix and others is forcing data centers to provide greater speed and more storage capacity. All of this size and speed comes at a price. Data centers generate a lot of heat that has to be whisked away by power-hungry air and liquid-cooling systems to keep the Internet’s engines from burning themselves out.
Efforts to combat this growing power consumption have been lukewarm, points out Diego Reforgiato Recupero, a computer scientist and electrical engineer at Italy’s University of Catania. In the March 29 issue of the journal Science, he shows that Internet traffic volume doubles every three years, yet this increase in usage has not been matched by a similar increase in network energy efficiency. Citing data on projected energy use increases for telecoms and Internet service providers, Recupero says the world’s data centers will consume 19 percent more energy in 2013 than they did a year ago.
As more people watch movies, make phone calls and share video online, the computers that support these services run hotter and require more energy to cool down their equipment. But that is only part of the problem. Companies such as Netflix and Google (owner of YouTube) configure their data centers to handle peak levels of network activity, even when such spikes in traffic are rare, because they want to make sure you can watch streaming videos on their sites with minimal disruption. Having the machines at the ready consumes energy, generates heat and demands cooling, which adds to the energy used.
To avoid becoming energy hogs and concomitantly adding more greenhouse gases into the atmosphere, these data centers need to smarten up, literally, using new approaches. Recupero points out two hardware management technologies in particular. One is “smart standby,” which places unused portions of computer server and networking equipment into very low power states. Another—dynamic frequency scaling—allows computer central processing unit usage to be throttled back on the fly when data traffic on a network is light. Both technologies should cut the amount of data-center heat that must be whisked away by high-power cooling systems.
Unfortunately, both smart standby and dynamic frequency scaling require the servers to be ramped back up when network traffic increases, Recupero acknowledges. If they don’t respond quickly enough, data transfers get delayed and Internet users suffer slower response times after they click on a link or spotty streaming when they play videos.
One of Recupero’s proposed solutions to the latency problem is to program greater intelligence into individual servers, network routers and other data center equipment that enables them to monitor their individual heat output and throttle their performance up or down to maintain a particular temperature (determined by whoever is managing the data center). Another option would be to configure the routing of data throughout the data center so that it takes the most efficient routes possible.
Not everyone shares Recupero’s concerns about “greening” the world’s data centers. Some who are more sanguine could point to a 2011 study by Stephen Ruth, a public policy professor at George Mason University indicating that the information and communications technology industry accounts for “only about 3–5 percent of the world’s electrical use.” (The transportation industry, by comparison, accounts for about 25 percent of world energy demand.)
Even if you cut in half the amount of power needed to run the Internet, you would still have a lot of other industries—transportation, in particular—putting a lot of carbon into the air, says Justin Rattner, chief technology officer of chipmaker Intel. Noting that “the Internet is already pretty green,” he suggests that the best way to make it even more energy efficient is to convince Internet companies that new technologies such as those suggested by Recupero can cut their energy bills significantly. “There’s a societal benefit here,” Rattner adds, “but it’s being driven by the economics of the situation more than some feeling.”