The TIA 942 standard, published by the Telecommunications Industry Association (TIA), provides a comprehensive framework for designing and building data center infrastructure. The standard focuses on ensuring the reliability, efficiency, and scalability of data centers, which are critical for supporting modern computing and storage needs.
TIA-942 uses "Rated 1, 2, 3, 4" to avoid trademark conflicts, but the industry commonly calls them Tiers I-IV. tia 942 standards
| Tier | Availability | Uptime per Year | Redundancy | Description | |------|--------------|----------------|------------|-------------| | | 99.671% | Up to 28.8 hrs downtime | None (N) | Basic infrastructure. Susceptible to disruptions from planned/unplanned work. | | Tier II | 99.741% | Up to 22 hrs downtime | Partial (N+1) | Redundant capacity components (e.g., one extra chiller). Still requires shutdown for maintenance. | | Tier III | 99.982% | Up to 1.6 hrs downtime | Concurrent maintainable (N+1) | Any component can be removed without shutting down IT load. Dual power paths. | | Tier IV | 99.995% | Up to 26.3 minutes downtime | Fault tolerant (2N or 2(N+1)) | Multiple active distribution paths. Can withstand a single failure without impact. | The TIA 942 standard, published by the Telecommunications
The latest published revision is (expected widely adopted in 2024-2025). Key updates include: | Tier | Availability | Uptime per Year