Data Center Tier Definitions & Up time

Data Center Tier Definitions & Up time

Tier 1 to 4 data center is a standardized methodology used to define uptime of data center. 

This is useful for measuring:

·        Data center performance

·        Investment

·        Return on investment (ROI)

• Tier 1 (Basic Capacity) = Non-redundant capacity components (single uplink and servers).
• Tier 2 (Redundant Capacity Components) = Tier 1 + Redundant capacity components.
• Tier 3 (Concurrently Maintainable) = Tier 1 + Tier 2 + Dual-powered equipment’s and multiple uplinks.
• Tier 4 (Fault Tolerance) = Tier 1 + Tier 2 + Tier 3 + all components are fully fault-tolerant including uplinks, storage, chillers, HVAC systems, servers etc. Everything is dual-powered.

Uptime for Different Tier Data Centers

Tier	Uptime %	Total Downtime
Tier 1	99.671%	1729.224 minutes or 28.817 hours
Tier 2	99.741%	1361.304 minutes or 22.688 hours
Tier 3	99.982%	94.608 minutes or 1.5768 hours
Tier 4	99.995%	26.28 minutes or 0.438 hours

Service Uptime Standards & Calculator

Service Up-time Standards & Calculator

To understand the meaning 99.99 or 99.9999 % up time, please see the below table

Name	Availability	Yearly	Monthly	Weekly	Daily
Six Nines	100.00%	31.536S	2.592S	0.6048S	0.0864S
Five Nines	100.00%	5.256M	25.92S	6.048S	0.864S
Four Nines	99.99%	52.56M	4.32M	1.008M	8.64S
Three Nines	99.90%	8.76H	43.2M	10.08M	1.44M
Two Nines	99%	3.65D	7.2H	1.68H	14.4M
Note: D=Day(s), H=Hour(s), M=Minute(s) & S=Second(s) Note: The calculation in above table is based on 30 Days month & the example shown below is considering total 365 days in a year.

The calculations are like this.

Total Days in an year	365
Hours in a day	24
Minutes in a Hour	60
Total Minutes in a Year (days*hours*minutes)	525600
Uptime %	99.99
Downtime % - After Deducting from uptime%	0.01

Formula to understand up time

Let says the UP-TIME % was 99.999 (5 Nines), means the downtime % would be (100-99.999)= 0.001%

So, Yearly Downtime would be=0.001% of Total Minutes in a year

                                                          =(0.001*525600)/100 = 5.256 Minutes in an Year.

                                                          = 5.256 Minutes in an Year.