Data Center Tiers
Intermediate – Cybersecurity
Reading Time – 1 minute, 37 seconds
The data center tiers are a classification of data centers based on the infrastructure, operations, and services the data centers offer. There are four tiers starting from a basic level 1 to rigid level 4. Every data center belongs to one of these tiers. This classification provide an industry-standard to reach data center infrastructure functionality.
The four tiers are also useful in measuring data center performance, investment, and ROI (return of investment). As the tiers increase, they balance the need for availability with the cost of redundancy. Therefore, higher tier levels provide better availability at a higher cost.
The below section contains a brief description of each tier.
A tier 1 data center has the basic facilities and infrastructure to operate as a data center. Tier 1 has no redundant capacity devices or components and it is composed of a single, non-redundant power and cooling distribution path. Hence, tier 1 is not fault-tolerant at all. It guarantees to provide 99.671% availability.
Tier 2 is an improvement over tier 1 with redundant components. Tier 2 is composed of a single, non-redundant power and cooling distribution path. Hence, power failures can entirely disrupt operations. Tier 2 data centers guarantee to provide 99.741 % availability.
Tier 3 is an update to the tier 2 with dual-powered equipment and multiple uplinks. Tier 3 provides the perfect trade-off between the cost and performance. Tier 3 composed of multiple, independent power and cooling distribution paths and redundant components that are concurrently maintainable. Tier 3 guarantees to provide 99.982% availability.
Tier 4 is composed of redundant components and multiple, active power and cooling distribution paths. All components such as servers, uplinks, storage, chillers, HVAC (heating, ventilation, and air conditioning) systems in a tier 4 data center are dual powered and fully fault-tolerant. Tier 4 contain strict security control methods and guarantees to provide 99.995% availability.