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Data Center Tiers: What Are They and Why They Matter for Web Hosting?

May 25, 2024


Websites aren’t just fluffy digital concepts. Knowing where your website data is located and how well it’s stored is a crucial factor in giving your website a strong foundation. Web hosts store your data in data centers – but they don’t all come equal.


That’s where data center tiers come in. These tiers help reveal what a web host can offer in terms of reliability and performance, so failing to choose the appropriate tier may cause future problems such as downtime or extra costs for your website.


Thankfully, we’re here to break down how data center tiers work, so you can better understand what to look out for when reading about a web host’s data centers.



What Are Data Center Tiers?


data center tiers

Data center tiers are a ranking system of data reliability. (Credit: AMAX)


Data center tiers are a standardized ranking system that shows how reliable the infrastructure of a data center is. Facilities are ranked from 1 to 4, with 1 representing the worst performance and 4 representing the best.


The Uptime Institute, an independent company, awards a data center with an international ranking and assesses the facility level primarily using the following criteria:


  1. Uptime guarantees
  2. Fault tolerance (a.k.a. the ability to handle both planned and unplanned disruptions)
  3. Service cost


This unbiased tier system provides an objective understanding of how a particular data center functions.


Oh, and another thing – it’s optional to have a rating, so not all data centers have one.


Nevertheless, the majority of large facilities still try to request an assessment from the Uptime Institute because an official rating helps with the following:


  • Building service credibility
  • Building trust and attracting potential clients
  • Marketing the facility’s capabilities
  • Planning for future upgrades and facility expansions


But, before a facility gets an official rating from the Uptime Institute, data center staff must send blueprints and side plans (a.k.a. the Tier Certification of Design Documents). After that, representatives from the Uptime Institute will visit the data center on-site to inspect operations and give a rating.



How Is The Standard For Data Center Tiers Determined?


Ratings are evaluated independently using The Uptime Institute’s Tier Certification. It establishes the standards for each data center tier and lists a number of standards that together make up the criteria for each tier. The following are the key standards for data center tiers:


  • Performance
    Since performance-based standards apply, any solution that satisfies the criteria for availability, redundancy, and fault tolerance is acceptable.
  • Technology neutral
    Because new, cutting-edge technologies such as web hosting security features continually reshape the landscape of digital transformation, tiers aren’t dependent on specific technologies to be categorized.
  • Vendor neutral
    Data centers are evaluated solely on their capabilities because the brand of technology they use isn’t taken into account when determining the tier.
  • Redundant systems
    The redundancy of critical systems is one of the important criteria used to rank data centers. Redundancy is basically a duplication of important information, making your system more reliable in case of an emergency. The rating can be higher the more redundant power, cooling, connectivity, and other components are available.



Comparing Each Data Center Tier


wooden blocks organize in tier

The higher the tier number, the better the tier is.


The Uptime Institute has certified four different data center tiers, which are the following:


Tier 1


The maximum uptime that a data center with a Tier 1 rating can promise is 99.671%. The data center in this tier, which is the lowest level, has a limited amount of built-in redundancy and other features.


But, housing servers in Tier 1 certified data centers are still going to be far superior to housing servers that are in an office closet or any other area that’s not specifically built for this type of operation.


Since these facilities are a lot less expensive to build and maintain, they are frequently used for non-critical systems. Though since there would be little advantage to having the certification, the majority of facilities that would qualify for Tier 1 certification won’t bother paying to go through the actual evaluation process.


Tier 2


With a 99.741% uptime guarantee, Tier 2 certified facilities promise a total of 1,360 minutes of downtime annually. So to reduce their amount of downtime, Tier 2 data centers must have some redundancy options.


Most of the time, a Tier 2 facility is dependent on a single source of power, a single source of cooling, and possibly multiple circuits for Internet connectivity. Hence, they frequently have built-in fail-safes, such as uninterruptible power supply (UPS) modules, cooling chillers, energy generators, and more.


Tier 3


Tier 3 data centers can promise an uptime of 99.982%, which equates to 95 minutes (or less) of downtime annually. From the Tier 2 rating, this represents a significant improvement. At this level, a facility provides notably higher levels of redundancy on all important data center components.


Moreover, power and cooling paths for Tier 3 facilities must also be redundant. For instance, a building or facility that has one main connection for utility power, but also has a diesel generator to turn on in the event of a commercial power outage. In most cases, the facility should also have a UPS system to maintain power to important systems until the diesel generator can provide the required power.


Tier 4


The highest tier for data centers is a Tier 4 facility. They have fully redundant systems and—most frequently—multiple sources of redundancy in place. Less than 26 minutes of downtime per year is possible with a Tier 4 facility’s 99.995% uptime.


A Tier 4 facility should have all critical systems on 2N redundancy, which refers to a standby system that’s fully mirrored and runs separately from the primary system. In most cases, this entails two complete cooling systems, two totally independent commercial power sources, and more.


Additionally, a UPS system and some sort of generator should be used as backups for each of those commercial power sources so that operations can continue uninterrupted.


A quick comparison of data center tiers


So to recap, here is a table to give you a clearer picture of how each tier is different from one another:


4 data center tiers comparison

Tier 4 is the best tier out of all the tiers. (Credit: Uptime Institute)



Which Data Center Tier Is Right For Me?


Even though higher tiers offer a more reliable service, selecting a Tier 3 or 4 data center isn’t always the right choice. Instead, decision-makers should decide on the data center tier that best suits their company’s needs.


Companies of a certain type tend to favor a particular tier too. The following is a breakdown of each tier’s usual customers:


  • Tier 1
    Small businesses and start-ups looking for the most affordable hosting option should use these data centers. Small businesses can tolerate more downtime regularly because they don’t have complex and demanding IT needs or 24/7 operations.
  • Tier 2
    These facilities are the first choice for SMBs looking for a more affordable, dependable alternative to a Tier 1 partner. Small to medium-sized businesses frequently use tier 2 facilities to host non-mission-critical databases or data backups.
  • Tier 3
    These data centers are perfect for big businesses with IT operations that require additional fail-safes. Large data hosting companies, especially those that host customer data are excellent candidates for this tier.
  • Tier 4
    These data centers are great for businesses with a flexible budget and a need for constant availability. Users of a Tier 4 facility are typically government agencies and large corporations with mission-critical servers and high customer or business demands.


Cost and uptime are typically the two main factors you should consider when selecting a tier. After all, it would be a waste of money to pay for a level 3 data center when a less expensive facility would do the trick. However, you should also consider that a lower-level tier such as a Tier 2 facility can also negatively affect your revenue, productivity, customer satisfaction, and reputation when you need a higher uptime.



What Database Tiers Do The Most Popular Web Hosts Use?


A data center is the base of operations for all the top web hosting companies. Since uptime is crucial for websites, web hosting facilities are typically on Tier 3 or higher.


The following are some of the web hosting companies that use them:


  • Hostinger
    At a low price, Hostinger has premium web hosting features, outstanding speed, and great uptime performance.
  • DreamHost
    One of the most recognizable names in the industry, DreamHost is great especially if you have servers within the US..
  • HostPapa
    While HostPapa might be small and independent, don’t let that fool you. They have great server speeds in Europe and North America which blows most of their competition.



On Choosing the Right Data Center


Now let’s wrap things up!


Data centers are vital for business operations. They house the most critical and proprietary assets that a business would need to run properly.


That’s why choosing a web host that uses excellent data centers is important. Different tiers have their own pros and cons, so choosing one can either make or break your business operations.


With that said, it’s always important to consider which one your business or website really needs and if it’ll help you achieve your goals.



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