Data Center Tiers are a system used to describe the specifications of a data center infrastructure in terms of redundancy and performance. The level of security and the amount of potential downtime over a year is considered for ranking the performance of a data center and is categorized into “Tiers”.

These Tier classifications are used to specify the facilities and capacity of the data center and do not indicate the level of excellence or quality of a data center. Meaning, a Tier I certification does not imply a low-standard facility or a Tier IV a high-standard facility.

Data Center Classification and Certification by the Uptime Institute

The Datacenter tier certification has been issued for the past 25 years to data centers that fit the criteria and standards for each tier class. The certifications are objective and reliable. They can be used to compare one data center infrastructure with another and help decide which facility suits your business needs more efficiently.

The certification issued by Uptime Institute for Data Center Tiers assures quality and optimized performance and adds to the facility’s credibility.

Operational Sustainability – The ability of a data center to meet the long-term goals based on behaviors and risks, and Topology is the major feature specified in this certification.

They use independent measures through which the facility is judged and certified. The criteria and values that Uptime Institute uses to evaluate the data centers are:

Performance: The institute accepts any solution adopted by the data center facility that meets availability, redundancy, and fault tolerance requirements.

Technology Neutral: The institute does not rate the data center based on the technology used for its components as long as they support sustainability operationally and meet the facility’s topology needs.

Vendor Neutral: The brands of the components used in the data center do not affect the judicial process by the institute.

The certification defines the criteria and guidelines for the data center’s maintenance, power, cooling, and fault capabilities. As the classification progresses, the Tier I data center can move. They are into a Tier II or higher class if required. The certification defines guidelines for expansion and growth as well.

Data Center Tiers and its Features

The Tier classes give you an insight into the redundancy and performance of a data center. Each class has specific downtime possibilities based on its configurations.

These are some essential terms and definitions to understand data center tiers:

Redundancy: In case of an error or emergency, some data center components that are critical for its functioning are duplicated and kept as backups and fail-safes. This process is called Redundancy, and it increases the reliability of a data center.

N+1: In case of a single failure or planned maintenance, an additional component is added to N, where N is the necessary capacity to run a data center.

2N: In this configuration, a completely mirrored or duplicated system is kept on standby and is independent of the primary system. If any component in the primary system fails, the mirrored system takes up slack and runs in its place.

These are the data center tiers given and certified by Uptime Institute and their features:

Tier I – Basic Capacity

Tier I data center has a single path for power and cooling and no (or few) redundancy backup components. This is because they lack the IT equipment to support and mainly do not require redundancy.

Tier I has an uptime of 99.671% and has 28.8 hours of predicted downtime annually.

Tier I class is the best fitted and affordable for tiny businesses that can afford the predicted downtime.

Tier II – Redundant Capacity 

Tier II is the same as Tier I but with some redundancy components. It has a single power input and added fail-safes for partial redundancy with the help of backup components like UPS modules, chillers, pumps, and energy generators.

Tier II has an uptime of 99.741% and predicted downtime of 22 hours annually.

They are more robust than Tier I, more reliable, and secure. Tiny businesses which can afford Tier II can opt for this.

Tier III – Comprehensive Redundancy

Tier III has N+1 redundancy with multiple paths for power and cooling and other systems. In addition, there are additional paths in place which kick up in case of failure, planned maintenance, or updates without taking the servers offline.

Tier III is not entirely redundant but has an uptime of 99.982% and predicted downtime of 1.6 hours annually. They use shared or reliant components for redundancy and are influenced by external mishaps.

They are most suited for SMBs and large-scale businesses that need 24/7 uptime needs throughout the year. Primarily, companies that cannot recoup from the losses of a breach or extended or frequent downtimes can opt for Tier III.

Tier IV – Fault Tolerant

Tier IV is the most robust class of data centers. They are fully redundant and have 2N or 2N+1 configuration. All components are mirrored, and the identical pieces kick start when any element in the primary system fails.

All components are supported by two generators, 2 UPS, and two cooling systems. They all are in independent paths so that a single failure will not affect them.

Tier IV has an impressive uptime of 99.995% and has a predicted downtime of 26.3 minutes annually.

This class is best suited for giant data centers and colocation centers, which require total protection, an uninterrupted network, and lesser budget constraints.

Tier V by Switch – Fault Sustainable

In 2017, Switch, a colocation and cloud service provider announced the fifth Tier class. Uptime Institute does not acknowledge this class, but they support it.

The Tier V data center offers:

• Heightened redundancy

• Long term power capabilities

• Zero roof penetration

• Physical and network security

• 100% use renewable energy

Tier 5 standards created by Switch enhance availability and reliability for colocation facilities.

How to Find the Right Data Center Tier for Your Business?

When choosing the tier class for your business, consider the following factors:

Security

Your business’s physical and network security features are necessary as the data center hosts and stores a critical asset: Therefore, making sure data and information are safe and breach-proof is essential. Also, depending on the type of data, you can decide to ease or strengthen your security features.

Availability 

Businesses that do not have systems online 24/7 for 365 days can opt for a lower Tier class. Companies that cannot recoup from a downtime loss will require a higher tier class. Depending on availability needs, choose your data center tier.

Budget Needs

SMBs and very small businesses can easily afford Tier I, II, or III. Then, based on the needs of the business and budget constraints, the data center tier can be decided.

Choosing a data center tier for your business can be challenging and overwhelming all at once. However, these certifications and guidelines can be easier to follow and implement with the help of a data center consultant like Mechartes, who can help you during the pre-design and design stage with their validation services. Get in touch today.