Achieving data center efficiency is not only challenging on a technology level, but as a matter of perspective as well. With no clear definition of “efficient” to begin with, matters are only made worse by the lack of consensus as to how to even measure efficiency and place it into some kind of quantifiable construct.
At best, we can say that one technology or architecture is more efficient than another and that placing efficiency as a high priority within emerging infrastructural and architectural solutions at least puts the data industry on the path toward more responsible energy consumption.
The much-vaunted PUE (Power Usage Effectiveness) metric is an unfortunate casualty of this process. The Green Grid most certainly overreached when it designated PUE as the defining characteristic of an efficient data center, but this was understandable given that it is a simple ratio between total energy consumed and the portion devoted to data resources rather than ancillary functions like cooling and lighting. And when implemented correctly, it does in fact provide a good measure of energy efficiency. The problem is that it is easy to game and does not take into account the productivity of the data that low-PUE facilities provide nor the need for some facilities to shift loads between resources and implement other practices that could drive up their ratings.
More of the IT Business Edge article from Arthur Cole