A facilities team reports that their data centre has a Power Usage Effectiveness (PUE) value of 1.6. A modernisation project reduces cooling and power distribution overhead, bringing PUE to 1.15. What does this change indicate about the proportion of energy reaching IT equipment?
- AThe ratio of cooling overhead to total IT load has increased, meaning more energy is now consumed by infrastructure than by compute.
- BTotal facility power consumption has doubled because efficient cooling systems require more redundant components.
- CThe data centre now operates at a higher ambient temperature, which lowers compute performance to compensate for reduced cooling capacity.
- DA greater share of total facility power now reaches IT equipment, as overhead losses from cooling and distribution have been reduced. Correct
Why A is wrong: A PUE moving closer to 1.0 always means overhead is decreasing relative to IT load, not increasing; a value of 1.15 leaves less overhead than 1.6.
Why B is wrong: Improving PUE does not imply doubling total power; it means a greater fraction of consumed power reaches useful IT work rather than being lost to overhead.
Why C is wrong: A lower PUE reflects more efficient energy use, not a trade-off against compute performance; modern liquid cooling can achieve low PUE values while keeping components well within thermal limits.
Why D is correct: PUE equals total facility power divided by IT equipment power; a PUE of 1.15 means only 15% of total energy is consumed by overhead, compared with 60% overhead at a PUE of 1.6. Reducing PUE toward 1.0 means progressively more energy is doing useful compute work.