What are some data center metrics and benchmarks, and where can I find them?
PUE (Power Usage Effectiveness)Created by members of The Green Grid, PUE is a metric used to determine the energy efficiency of a data center. The data center's PUE is calculated by dividing the amount of incoming power by the power used by the IT infrastructure. Expressed as a ratio, efficiency improves as it approaches 1. Data center PUE typically ranges from around 1.3 (good) to 3.0 (bad), with an average of 2.5 (not so good).
DCiE (Data Center Infrastructure Efficiency)Created by members of The Green Grid, DCiE is another metric used to determine the energy efficiency of a data center, and it is the reciprocal of PUE. It is expressed as a percentage and is calculated by dividing the power of the IT equipment by the total power of the facility. Efficiency improves as DCiE approaches 100%. A data center's DCiE typically ranges from 33% (poor) to 77% (good), with an average DCiE of 40% (not so good).
LEED CertifiedDeveloped by the U.S. Green Building Council (USGBC), LEED is an internationally recognized green building certification system. It provides third-party verification that a building was designed and constructed using strategies intended to improve performance across all metrics: energy savings, water efficiency, CO2 emissions reduction, indoor environmental quality, resource management, and sensitivity to its overall environmental impact. For more information about LEED, go to www.usgbc.org.
The Green GridThe Green Grid is a global consortium of non-profit organizations, government agencies, and educational institutions dedicated to improving energy efficiency in data centers and business computing ecosystems. The Green Grid does not endorse specific product or solution vendors and instead seeks to provide the entire industry with recommendations on best practices, metrics, and technologies that improve the overall energy efficiency of data centers. For more information about The Green Grid, visit www.thegreengrid.org.
Telecommunications Industry Association (TIA): The TIA is the leading trade association representing the information and communications technology (ICT) industries worldwide. It helps develop standards, gives ICT a voice in government, provides market intelligence, certification, and promotes business opportunities and global environmental compliance. Supported by its 600 members, the TIA enhances the business environment for companies involved in telecommunications, broadband, mobile wireless, information technology, networking, cable, satellite, unified communications, emergency communications, and technology greening. The TIA is accredited by ANSI.
TIA-942: Published in 2005, the Telecommunications Infrastructure Standards for Data Centers was the first standard to specifically address data center infrastructure and was intended for use by data center designers at the beginning of the development process. TIA-942 covers:
• Site space and design
• The cabling infrastructure
• Reliability in levels or tiers
• Environmental considerations
Reliability levels – The TIA-942 standard has been adopted by ANSI for reliability levels based on its usefulness in the overall evaluation of redundancy and availability in a data center design.
Tier 1 Basic – no redundant components (N): 99.671% availability
• Sensitive to disruptions to planned and unplanned activities
• Single path for feeding and cooling
• It must be completely switched off to perform preventive maintenance
• Annual downtime is 28.8 hours
Tier 2 – Redundant components (limited N+1): 99.741% availability
• It is less susceptible to disruptions from planned and unplanned activities
• Single path for power and cooling includes redundant components (N+1)
• Includes a raised floor, UPS and generators
• Annual downtime is 22.0 hours
Tier 3 – Concurrent maintenance (N +1): 99.982% availability
• It allows planned activities (e.g., scheduled preventive maintenance) without interrupting hardware operation (unplanned events can still cause interruption).
• Multiple power and cooling paths (one active path), redundant components (N+1)
• Annual downtime is 1.6 hours
Tier 4 – Fault Tolerant (2n +1): 99.995% availability
• The planned activities do not interrupt critical operations and can sustain, at least in the worst-case scenario, an unplanned event without impacting the critical workload
• Multiple active power and cooling paths
• Annual downtime is 0.4 hours
Due to the duplication of infrastructure (and space) in a Tier 3 facility, a Tier 4 facility will have a much higher cost to build and operate. Consequently, many organizations prefer to operate at the more economical Tier 3, as it achieves a reasonable balance between CAPEX, OPEX, and availability.
Uptime Institute: It is a non-profit organization created to achieve consistency in the data center industry. The Uptime Institute offers education, publications, consulting, research, and conference series for the enterprise data center industry.