The Performance Indicator

In June 2016, the Green Grid introduced a new group of data centre metrics “The Performance Indicator” (PI).

The PI complements existing PUE, WUE and other Green Grid metrics. This group of metrics allows businesses to set targets and view how data centres  are performing against targets.

The PI considers three key aspects of a data hall:

• IT Thermal Conformance;
• IT Thermal Resilience; and
• Infrastructure Energy efficiency (based on PUE)

Dr Julien de Charentenay, Head of Building Physics at RED, explained the particularity of the PI metric by saying “the new metric identifies the performance gap between the operation and the targeted design by scoring three key aspects [conformance, resilience and efficiency] on a scale of 0 to 100% and would ideally be evaluated continuously to measure improvement rather than assessed at fixed interval”.

The Performance Indicator metric development was led by Mark Seymour, CTO at Future Facilities, with over 50 members of the The Green Grid joining the work item. The metrics identify four levels of audit that range from rack level temperature measurement (level 1) to the use of detailed temperature measurement to produce a calibrated Computational Fluid Dynamics model to model future states (level 4).

While the new metric does not radically change how data centres are designed, it does bring a novel approach in presenting the design characteristics on both a data hall and data centre basis. We are incorporating the IT Thermal Conformance and IT Thermal Resilience aspect of the metric in our reporting on data centre design. This assist us in explaining to end-users that it is acceptable to relax the IT inlet temperature under failure scenario, even though in a perfect world, data hall temperature should not be affected by failure of redundant units.

The Performance Indicator Tool can be downloaded from The Green Grid at http://www.thegreengrid.org/en/Global/Content/Tools/PerformanceIndicatorTool