The metrics we need for a green cloud

“Calculating the subscription costs of cloud computing is easy. But how can IT directors compare this to the cost of existing operations? They must analyse costs across the IT estate, including support staff, electricity and supporting infrastructure to make a financial case for cloud computing.” — Janet Lin, Verdantix Senior Manager in the New York office

Last week’s Verdantix and AT&T report on the energy and carbon emission savings to come from cloud computing is the latest in a long line of studies stating the obvious: Shifting computing from inefficient, dispersed data centers to highly efficient, centralized cloud data centers should save everyone energy. But there are several data-center-efficiency metrics you will need to know to figure out how to differentiate green-cloud-marketing hype from reality.

For example, there has been a lot of talk about power usage effectiveness (PUE) and data center infrastructure efficiency (DCIE); but equally important is the Uptime Institute’s corporate average data center efficiency (CADE), which measures utilization of both IT and data center facility assets across the enterprise. No doubt, cloud-computing providers can offer far better PUE, DCIE and CADE measures than the data centers they’ll replace. Just compare the 2.0 PUE industry average to hyper-efficient cloud data centers from Facebook, Google, Cisco, Amazon and Microsoft with PUEs that approach the perfect figure of 1.0. In my weekly update at GigaOM Pro, I detail these and other metrics, illustrating how they could help the IT industry understand the true energy footprint of cloud computing, and how more transparency could change the industry.