An organization comprised of IT professionals calling itself Green Grid published a paper in February, 2007 on efficiency.  That paper was widely misunderstood and the organization has regrouped and released a new metric on data center efficiencies.  This new effort hopes to create an industry-wide consensus on exactly what "going green" means.

When data centers look to save power by using "green" equipment, are they successful?  Is the purchase and use of green equipment in certain areas more beneficial than in other areas?  For example, if a slew of CPUs, each consuming 100 watts of power during peak operations, are replaced with CPUs consuming 50 watts, how significant is that 50% reduction in raw power consumption in overall costs?  It might also cost less to cool the system, meaning the 50% savings on the CPU side results in actually a 65% increase in overall energy savings, for example.

The Green Grid's new paper is called Data Center Infrastructure Efficiency (DCiE).  It builds on the previous attempt called Data Center Efficiency (DCE).  The DCiE introduces hard formulas and solid definitions which remove ambiguity and place significance on industry-wide, accepted terms.  For example, the group defines Power Usage Effectiveness (PUE) as Total_Facility_power / IT_Equipment_power.  It is a pretty straight-forward formula, and even an obvious recognition of intention through the formula, but without it being explicitly stated by a governing body there could be hundreds of similar definitions running around the data center formula vaults.  The paper goes into much greater detail, including explicit definitions about what each of those terms encompasses.

The Green Grid hopes to establish an industry standard.  Its members include employees from AMD, Microsoft, Dell, Rackable Systems, APC, HP, Sun, IBM, Intel, Spraycool, VMware and more.  Their first paper was published in February, 2007, entitled "Green Grid Metrics: Describing Data Center Power Efficiency".  Their second paper is available for download at their website.