On the 3rd April The Green Grid announced their agreement with the US, EU and Japan on a set of guiding principles for data centre energy efficiency metrics but Australia has other plans.
In Australia NABERS for Data Centres is under development but what will this new measurement provide that isn't already available in existing data centre measurement and assessment tools like The Green Grid's PUE and DCiE?
The Department of Environment, Climate Change & Water (NSW) and the Department of Environment, Water, Heritage and the Arts (Federal), who are partners on the NABERS initiative, call it the first of its kind in the world - a methodology and energy efficiency rating tool based on the existing NABERS energy rating for buildings.
The project started with the commission of a report on data centres, their energy use, existing standards and the current Australian situation in the first half of 2009.
The report essentially summarises the current situation based on existing research in the US; that the need for data centres is rapidly increasing; and the fact that computing is becoming a commodity. It also states that outside server power consumption, storage is the second foremost energy consumer with energy use accounting for 10-15% of total equipment load in the typical data centre.
Outside the computing infrastructure, the air conditioning and cooling system is the highest energy consumer, with a 30-40% share.
Typical energy split in a Tier 3 data centre, source: Equipment Energy Efficiency Equipment Committee (Australia)
The report also acknowledges the following current data centre energy efficiency metrics:
- Power Usage Effectiveness (The Green Grid)
- Data Centre Infrastructure Efficiency (DCiE) (The Green Grid)
- Energy Star Data Center Infrastructure Rating (US EPA)
- SpecPower (SPEC)
However it notes that PUE and DCiE performance are both impacted by ambient temperature, requiring the metrics to be averaged over annual seasonal cycles; and that both metrics lack a reference to useful output (i.e. load).
The proposed NABERS standard will be divided into three different measurements:
- Data Centre Support Facility Rating - targeted at co-location (co-lo) data centres and facilities managers who have no control over type, amount or operation of equipment. It will be based on but extend PUE.
- Data Centre Tenancy Rating - targeted at a data centre renting space with a co-lo. In this scenario the assumption is the organisation has no control over the support services provided by the data centre. This metric will be based on the amount of IT workload performed and the greenhouse gas emissions generated.
- Whole Data Centre Rating - assumes a full control situation for the organisation. This metric will combine the previous two.
The rating also tries to rule out subjectivity by assuming all work actions are equal as opposed to assessing the potential "usefulness" of the work performed; and it will be calculated by an approximate count of the total number of actions performed.
The six workloads counted will include:
- Storage Capacity
- Storage Utilisation
- Network Capacity
- Network Utilisation
- Server Capacity
- Server Utilisation
The next step for the metric development is data collection and analysis which will then culminate in a methodology report to be put forward to a technical advisory group.
