Data Center tiers – What Are they?

Data center tiers are a method of categorizing data centers based on their infrastructure’s availability, redundancy, and reliability. This classification system clearly explains a data center’s anticipated performance and uptime. Organizations such as the Uptime Institute or the Telecommunications Industry Association (TIA) are usually responsible for defining and outlining these tiers.

What are Hosting Tiers?

When discussing hosting tiers, we refer to the various levels or types of hosting services providers offer. These tiers describe the resources, features, and support the hosting service provides. Hosting tiers are designed to clarify the level of service and infrastructure reliability offered by a hosting provider. Each hosting service level—such as shared, VPS, dedicated, and cloud—has its own set of characteristics and capabilities, categorized into tiers. Data center infrastructure is also classified into tiers (Tier 1, Tier 2, Tier 3, Tier 4), where generally, the higher the tier, the greater the availability.

The Four Data Center Tiers

Data center tiers are a method for standardizing the classification of data center facilities based on their security, redundancy, and availability levels. They are an effective way to communicate essential details about data center facilities quickly. The Uptime Institute is responsible for setting the standard for data center tiers and assigning these tiers to facilities based on various factors, some of which must be publicly disclosed. Each tier and its requirements are listed below.

Tier One

  • Basic site infrastructure with expected availability of 99.671%
  • Single non-redundant distribution path with non-redundant capacity components
  • Planned work and outages will require most or all of the site to be shut down

Tier Two

  • Meets or exceeds all Tier 1 requirements
  • Redundant site infrastructure capacity and single, non-redundant distribution path with expected availability of 99.741%

Tier Three

  • Meets or exceeds all Tier 1 and Tier 2 requirements
  • Concurrently maintainable site infrastructure with an expected availability of 99.982%
  • Multiple independent distribution paths, but only one path required
  • The equipment is dual-powered & fully compatible with the topology of the site’s architecture

Tier Four

  • Meets or exceeds all Tier 1, Tier 2, and Tier 3 requirements
  • Fault-tolerant site infrastructure with electrical power storage and distribution facilities with an expected availability of 99.995%
  • Fault-tolerant with multiple, independent, physically isolated systems that provide redundant capacity components and multiple, independent, diverse, active distribution paths simultaneously serving the computer equipment. Independently powered cooling and power were supplied after infrastructure failure.

Next Steps

Each hosting tier offers different performance levels, scalability, control, and cost. Choosing the right tier depends on factors such as the size of your website or application, expected traffic volume, budget, and specific technical requirements. When selecting a hosting tier, you must assess your needs carefully and consider factors like uptime guarantees, support quality, and additional features (like security and backup options). Contact us today with your questions about the cloud or cloud enablement services. Our experts are always happy to discuss your needs.