center traffic is set to grow fourfold, hitting 6.6 zettabytes a year by 2016. And cloud traffic, the fastest-growing component of data center traffic, will grow 44 percent annually, or sixfold, in the same time frame. So says Cisco's second annual Global Cloud Index.
To put the growth into perspective, 6.6 zettabytes is equivalent to 92 trillion hours of streaming music, 16 trillion hours of business Web conferencing, and 7 trillion hours of online high-definition (HD) video streaming.
"This year's forecast confirms that strong growth in data center usage and cloud traffic are global trends, driven by our growing desire to access personal and business content anywhere, on any device," said Doug Merritt, senior vice president of Corporate Marketing at Cisco.
"When you couple this growth with projected increases in connected devices and objects, the next-generation Internet will be an essential component to enabling much greater data center virtualization and a new world of interconnected clouds."
What's Driving the Cloud?
Cisco predicts global cloud traffic will account for nearly two-thirds of total global data center traffic by 2016. Globally, cloud traffic will grow from 39 percent of total data center traffic in 2011 to 64 percent of total data center traffic.
In fact, global cloud traffic will grow faster than overall global data center traffic. The transition to cloud services is driving global cloud traffic at a growth rate greater than global data center traffic.
"The biggest driver is that the network has become a more cost-effective storage repository. With computing in the old days, the cheapest way to store data was to put it on a local hard drive," said Zeus Kerravala, principal analyst at ZK Research.
"When you look at the price performance of the network, considering broadband, fiber, FiOS and other networking technologies, from a consumer standpoint it's more cost-effective to leverage the network for content. Instead of storing the content locally, you just go to the network and get it when you want it."
From 2011 to 2016, data center workloads will grow 2.5-fold and cloud workloads will grow 5.3-fold, Cisco predicted. In 2011, 30 percent of workloads were processed in the cloud, with 70 percent being handled in a traditional data center.
Cisco also predicts 2014 will be the first year when the majority of workloads shift to the cloud. By then, 52 percent of all workloads will be processed in the cloud versus 48 percent in the traditional IT space. And by 2016, 62 percent, or nearly two-thirds of total workloads, will be processed in the cloud.
Finally, Cisco predicts the average workload per physical cloud server will grow from 4.2 in 2011 to 8.5 by 2016. In comparison the average workload per traditional data center physical server will grow from 1.5 in 2011 to 2.0 in 2016.