Data center Tier classification

Not all data centers are made equal, and there are many differences when it comes to both quality and performance: From system technology and energy efficiency to data protection and even administrative organization—many factors impact the availability of a data center.

Standardized rankings

In the 1990s, the Uptime Institute introduced the Tier classification to help compare the performance of data centers. The resilience of a data center is classified into one of four levels, whereby Tier 1 is the lowest level and Tier 4 denotes a highly available data center. Among other things, the international standard also defined criteria for maintenance, power supply, cooling, and possible errors that data center providers should be aware of.

Tier 1 data centers

Data centers that operate under Tier 1 of the Tier classification provide basic infrastructure. No redundancy is required in this Tier and systems are not fault-tolerant. What’s more, it is not possible to carry out maintenance while a data center is running. The availability of a Tier 1 data center is 99.67 percent, which corresponds to annual downtime of 28.8 hours.

Tier 2 data centers

The availability of Tier 2 data centers rises to 99.75 percent thanks to redundant components and improved heat dissipation. However, there are still no duplicate supply routes at this level, which means the maximum downtime per year is 22 hours.

Tier 3 data centers

Tier 3 provides redundancy: Not only are servers duplicated, but there are also two separate networks for both power supply and air conditioning. Data centers are also divided into several fire zones, which significantly increases the resilience of the data center and makes the system more tolerant to faults. What’s more, maintenance can be carried out while the data center is running thanks to redundancy. With an availability of 99.98 percent, Tier 3 data centers boast downtime of just 1.6 hours a year.

Tier 4 data centers

Data centers in the highest Tier classification are fully redundant and have duplicated, active supply routes. With an availability of 99.991 percent, users enjoy an extremely fault-tolerant system that has yearly average downtime of only 0.8 hours.

The right data center for every need

With a view to the security provided, companies should not simply opt for the cheapest solution when choosing a colocation data center—they should also pay attention to the Tier classification. ITENOS Tier 3 data centers not only boast extremely high availability at very accessible prices but they’re also designed for sustainability. 24/7 service complete with a German service desk provides reliability where you need it most: Securing your business operations.