A data center can achieve an excellent facility PUE while still operating large amounts of lightly utilized IT equipment. Sustainability therefore requires attention to both infrastructure efficiency and the effectiveness of the IT equipment consuming the energy.
Use server-focused KPIs
ISO/IEC 30134-4:2017 defines IT Equipment Energy Efficiency for servers (ITEEsv), while ISO/IEC 30134-5:2017 defines IT Equipment Utilization for servers (ITEUsv). Both standards have 2025 amendments.
Separate efficiency from utilization
Energy-efficient hardware can still waste energy when oversized or poorly utilized. Conversely, high utilization should not be pursued in a way that removes necessary performance, resilience or capacity headroom.
Use workload and lifecycle data
Server inventory, utilization trends, virtualization density, application demand, hardware age and refresh strategy can support decisions about consolidation, retirement and capacity planning.
Coordinate with resilience
Consolidation should not collapse independent failure domains or remove capacity needed for maintenance and failover. Sustainability improvements must remain compatible with the service-availability objective.
Measure the whole outcome
Facility PUE, IT equipment efficiency, IT utilization, renewable-energy share and workload performance should be interpreted together. No single KPI provides a complete sustainability picture.
References
- ISO/IEC 30134-4:2017 and Amendment 1:2025, IT Equipment Energy Efficiency for servers (ITEEsv).
- ISO/IEC 30134-5:2017 and Amendment 1:2025, IT Equipment Utilization for servers (ITEUsv).
