Introduction to Data Centre Tiers

Understanding data centre tier levels is essential when deciding on an IT infrastructure solution for your business. Simply put, these tiers are a method used to describe and evaluate the service offering and infrastructure of a data centre, in relation to business requirements. They’re usually the same across the data centre industry, even if the designs of the data centre are different. The data centre tier classification system focuses on performance, uptime, and redundancy. This allows businesses to choose an ideal data centre solution based on their requirements for their technology infrastructure and service level.

What are data centre tiers?

Data centre tiers were first introduced by the Telecoms Industry Association, with an updated version released by the Uptime Institute. These are the most widely used across the industry and comprise four levels: Tiers 1 through 4. The specifications for each tier are progressive, which means that a data centre that fulfills Tier 2 will fulfill all the requirements of Tier 1, plus those of Tier 2.

For example:

Tier 4 = Tier 3 + Tier 2 + Tier 1

What are data centre tier classification standards?

The following are the factors that are considered when setting data centre tier standards:

1. Availability, redundancy, and uptime: How long is this data centre expected to function annually, and what steps are in place to minimise downtime?

2. Efficiency and sustainability: How efficiently does the data centre utilise its resources, and what’s its anticipated lifespan in the face of emerging technologies?

3. Cost: What are the operating expenses of the data centre?

4. Security: How is the data centre safeguarding against data breaches and other risks?

What is a Tier 1 data centre: Standards, requirements, and specifications

Typical uptime: 99.6+%

Tier 1 data centres have been derisively referred to as ‘warehouses with power’, as the investment in these is usually driven by cost and time to market. They tend to be tactical choices for businesses that need support that fits in their budget or for businesses that don’t rely on real-time service outputs. They’re designed with a single input for power and cooling, with little to no provisions for redundancies or outages.

What is a Tier 2 data centre: Standards, requirements, and specifications

Typical uptime: 99.7+%

A Tier 2 data centre is very similar to a Tier 1 data centre, as they typically have one path for power and cooling. However, Tier 2 data centres account for redundancies with extra equipment on site. These tend to be kept separately from main equipment and only used in the case of a total outage.

What is a Tier 3 data centre: Standards, requirements, and specifications

Typical uptime: 99.98+%

Data centere that are classified as Tier 3 are the most common type used by businesses worldwide. Tier 3 data centre requirements include all of the prior tiers but add a layer of reliability and long-term viability for businesses looking for year-on-year support. Businesses use Tier 3 data centres as strategic assets, as the infrastructure they form part of is built beyond their current IT requirements. With rigorous uptime requirements, they’re designed with multiple paths for cooling and power. Measures for multiple redundancies are in place, with additional equipment taking power and network connection from independent entries, allowing for concurrent availability.

What is a Tier 4 data centre: Standards, requirements, and specifications

Typical uptime: 99.99+%

Tier 4 data centres are the highest possible classification for a data centre and typicallycosts twice as much to build as a Tier 3 data centre. This is because every piece of equipment in the facility has a backup, powered independently, with a seamless transition in case of failure. This calibre of data centre is built to have no single point of failure, with multiple power and cooling paths into equipment and more than one connection to the main power grid. This tier of data centre isn’t generally as common as the other tiers, and businesses tend to choose Tier 3 options over the increased cost of a Tier 4. A proactively maintained and tested Tier 3 data centre infrastructure will serve most businesses better than a single Tier 4 data centre. The phenomenon of Data Gravity (where data attracts data) means that optimising data storage across facilities holds less risk than consolidating everything into a Tier 4 centre.

Conclusion

The data centre classficiation system can be a useful framework for aligning your business requirements with a potential data centre provider. When researching for enterprise IT solutions, it’s imperative to ask the right questions, talk to the team running the facility to find out what kind of testing and monitoring they do routinely. Tier 3 fits the requirements for most businesses, with a balance between service and resource outlay. A strategic solution often splits requirements across multiple Tier 3 centres, giving your business a higher uptime than one poorly run Tier 4 data centre.

With over 300+ data centres worldwide, we have a team of experts that can help at any time and provide our recommendations as it applies to your specific deployment. Contact us to learn more.

Frequently Asked Questions (FAQs) About Data Centre Tiers

What are the main standards for data centres?

The main standards for data centres are determined by The Uptime Institute's Tier system. This classification system provides a standardised way to measure a data centres level of resilience and availability.

What is the highest-tier data centre?

The highest widely recognised tier data centre classification is Tier 4. A Tier 4 data centre is designed to be fully fault-tolerant, with redundant systems for all critical components. It offers the highest level of availability and has an uptime of 99.995%. It can withstand a wide range of potential disruptions and offers the most reliable infrastructure.

What is Tier 3 data centre requirements?

Tier 3 data centre requirements include redundant components for power and cooling, multiple independent distribution paths for power, and concurrent maintainability, allowing for planned maintenance without downtime. It should also have a minimum of N+1 redundancy for its critical systems.

What is Tier 4 data centre criteria?

Tier 4 data centre criteria include all the requirements of Tier 3, but with additional features like fault tolerance, which means there are no single points of failure in the infrastructure. It should have multiple active power and cooling distribution paths, as well as a fault-tolerant design for mechanical and electrical systems.

What is the tier specification of a data center?

The tier specification of a data centre refers to its classification, according to The Uptime Institute's Tier system, which evaluates its resilience and availability. The classification is based on specific criteria such as redundancy, concurrent maintainability, and fault tolerance. The higher the tier, the more reliable and available the data centre.