What is Tier? Standards of Tier 1-2-3-4

What is Tier? Standards of Tier 1-2-3-4

Why tiers are important?


Tier is a type of certificate that sets standards for data centers therefore it is important for data center and data room costumers and providers. Besides, it is called as ‘’Up-time Institute.‘’ Today we point out what is tier and tier standards.

Tier standards have an important place for companies and providers. In other word, Tier standards are quality certificate for provider companies. Today we will examine what is tier, standards of the tier and difference of tiers.


What is Standards of the Tier?


there is a tier 1-2-3-4 algorithm

We point out the standards of tier;

Tier 1


Tier 1 data centers maintenance is made by companies two times in a year for 12-hour. Besides, data centers may be a lot technical problems about 2 hours in a year. Therefore, the total annual effect of all these treatments and unexpected errors is 28.8 hours or 99.676% Noncritical systems are a type of certificate that is determined for non-hardware redundant productivity centers.


Tier 1;


  • 99.671% up-time guarantee, downtime posture tolerances as follows
  • Daily: 4 min, 44.3 sec
  • Weekly: 33 min, 9.8 sec
  • Monthly: 2 hours, 24 min, 11.9 sec
  • Annual: 1 day, 4 hours, 50 min, 22.4 secs


Tier 2


Tier 1 + is the availability of replacement equipment and components in case of system failure. Also, tier 2 data centers are maintenance three times in 2 years and the data centers encounter unexpected problems about one time.

The back-up systems of these data centers offer some maintenance privileges and help to make sure that some IT equipment is not affected by failures. for that reason, the average annual deduction can be expressed as 22 hours or 99.741% availabilities.


Tier 2;


  • 99.741% up-time guarantee, downtime tolerances as follows
  • Daily: 3 min 43.8 sec
  • Weekly: 26 min 6.4 sec
  • Monthly: 1 h 53 min 31.0 sec
  • Annual: 22 h 42 min 12.5 sec


Tier 3


With Tier 1 + Tier 2 + requires redundant power equipment, power, generator power supply and up-link connections. However, Tier three is better instead of tier 1 and tier 2.  Because tier 3 data centers are suitable for simultaneous maintenance. Therefore, annual maintenance outages are not considered. Thus it can provide many advantages for providers and costumers.

Unexpected breakdowns in operation errors or site components may cause power outages in the data center. According to the data obtained from real data centers, there are unexpected closures of 4 hours in every 2.5 years. This ratio means 99.982% availability for Tier 3 data centers.


Tier 3


  • 99.982% up-time guarantee, downtime downtime tolerance as follows
  • Daily: 15.6 sec
  • Weekly: 1 minute 48.9 sec
  • Monthly: 7 minutes 53.4 sec
  • Annual: 1 h 34 min


Tier 4


In addition to Tier 1 + Tier 2 + Tier 3 +, all components, including up link connections, storage, air conditioning, server and network systems, etc., must be configured to operate at any time and configured to meet the possibility of zero failures.

The Tier 4 data center is robust and fault-tolerant. As a result of the measurements taken, data center providers observe that there are 4-hour interruptions every 5 years. In other words, these interruptions are equal to 0.8 hours per year and 99.990% accessibility is calculated.

Different faults may occur in different components within the data centers. However, they do not affect end users. Because the redundant structure is designed to protect against these errors.


Tier 4


  • 99.995% up-time guarantee, downtime posture tolerances as follows
  • Daily: 4.3 sec
  • Weekly: 30.2 sec
  • Monthly: 2 min 11.5 sec
  • Annual: 26 min 17.8 sec