Power Usage Effectiveness (PUE) values are drawn from the Lawrence Berkeley National Lab 2024 U.S. Data Center Energy Usage Report. We use the reported range of 1.1–2.4x as representative of hyperscale to legacy enterprise data centers.

GPU comparisons are limited to NVIDIA data center GPUs across four generations: Volta (V100), Ampere (A100), Ada Lovelace, and Hopper (H100). AMD and Google TPU workloads are excluded from the hardware efficiency analysis.

Carbon intensity by grid region uses IEA country-level averages (gCO₂/kWh). Sub-regional variation (e.g. ERCOT vs PJM within the U.S.) is not captured. This may understate variance in large, grid-diverse countries.

When data centers report renewable energy percentages, we treat these as Power Purchase Agreement-based figures, not real-time 24/7 matching. Actual hourly carbon intensity may differ from annual averages.