Skip to content

Data Center Tier Rankings: What Do They Mean?

When you think about tiers, think about level of service. There are a total of four tiers when it comes to data center ratings, and these tiers are called the “Tier Standard System”. This rating system was introduced by The Global Data Center Authority’s Uptime Institute to provide a ‘benchmark’ for the data center industry. So, what do these tier rankings mean?


Tier I

Tier I data centers are the least sophisticated out of the group. Tier I centers are allowed the most amount of downtime, at 28.8 hours per annum. They also are allowed the least amount of uptime at 99.671% per annum.

For small businesses looking for a cost-effective solution, tier I data centers may work fine. While they don’t have most of the features that higher-ranked centers have, they may include at least a backup cooling system and generator. If you choose to go with a tier I data center, there are a few things you should consider first:

  • Are the location managers dedicated to physical security?
  • Check the humidity and location of the tier I data center – it is important for your chosen data center to be well maintained to avoid any mechanical issues.


Tier II

Tier II colocation data centers are a step up from tier I but do not require the amount of performance hardware as top-tier centers do. This type of data center gives businesses a chance to customize their services for the price point and performance they desire.

To become a tier II data center, no more than 22 hours of downtime are allowed per annum. The minimum amount of uptime in one year must be at or above 99.741%. Tier II guarantees more efficiency and can handle more clients. Most small business servers use this level, because the decline in features from tier III to tier II is massive, causing tier II to be significantly more affordable for small to medium-sized businesses.


Tier III

For growing businesses, or any business that is considered larger than a small to medium-sized business, typically a tier III data center is what you want storing and protecting your servers. To become a Tier III data center, 72 hours of protection from power outages without using an outside source is a must. These data centers also must have an N+1 fault tolerance, meaning routine or scheduled maintenance can be performed without disrupting the system.

The downtime allowed for tier III data centers is 1.6 hours per year, and the minimum amount of uptime must be 99.982% per annum. Here are just a few benefits of utilizing a Tier III data center:

  • Dual Power Sources
  • Redundant Cooling
  • Network Streams are fully backed-up
  • High Guaranteed Uptime and Low Downtime
  • More budget-friendly than Tier IV but with most of the same features.

If you are concerned about efficiency, but not about being attacked by malicious hackers, a Tier III data center should be right for you.


Tier IV

Tier IV, the top-tier level data center, has twice the site infrastructure of Tier III. This type of data center is ideal for anyone needing to host a mission-critical server, or to ensure high levels of security. Here are a few benefits that come with utilizing a Tier IV data center:

  • 96 hours of protection from power outages
  • No more than 26.3 minutes of downtime per year
  • 995% minimum uptime per year
  • 2N+1 Infrastructure – two times the amount required for operation plus a backup.
  • No single error or outage can cause the system to shut down.


Simple Helix

Simple Helix is designed to a tier IV Standard. However, due to site constraints, we can only house 72 hours of fuel on-site. This makes Simple Helix a tier III equivalent with tier IV redundancy. It can be hard to understand what data center tier fits your business requirements. Contact Simple Helix today at (256) 704-1041 or to discuss your needs and start your journey toward data resiliency.




Blog comments