If you are in the market for superior data center services, you may be familiar with the ‘Tier system.’ The four-tier system, used for classifying (and simplifying) different levels of data center reliability and uptime as an industry standard approach, was developed by The Uptime Institute, which is an independent division of The 451 Group. The Uptime Institute provides education, publications, consulting, certifications, conferences and seminars, independent research, and thought leadership for the enterprise data center industry and for data center experts and professionals.
The tier system is a key component referred to by customers seeking data center and colocation services and parties directly involved with planning and designing data centers. The system delivers a simple, operative description of data center site infrastructure design topologies. To understand the system, below is a description of what each of the four tiers represent, as defined by The Uptime Institute:
■ Tier 1 represents a data center with a single path for power and cooling distribution, without redundant components and providing a minimum of 99.671% uptime availability
■ Tier II represents a data center with a single path for power and cooling distribution, with redundant components and providing a minimum of 99.741% uptime availability.
■ Tier III represents a data center with multiple active power and cooling distribution paths, but only features one path that is active. It has redundant components, and is concurrently maintainable, providing a minimum of 99.982% uptime availability.
■ Tier IV represents a data center with multiple active power and cooling distribution paths, has redundant components, and is fault tolerant and provides a minimum of 99.995% uptime availability. This highest ranked tier includes everything that tiers 1 through 3 include, plus fully fault-tolerant components that include uplinks, storage, chillers, HVAC systems, servers, etc.; and everything is dual powered.
Companies commonly utilize the four tiers as a means of measuring a data center’s performance. For customers, this may be a deciding factor when choosing a collocation company. For Investors, they may choose to enhance an existing data center to improve its Tier or build a data center according to the Tiering specification.