A Jefferies report exposes a stark performance divide among European data centers, where identical sustainability metrics mask vastly different operational realities. The analysis of over 700 facilities reveals that physical scale is the primary driver of efficiency, with very large sites consistently outperforming smaller ones due to advanced infrastructure and tighter controls. 70% of reporting EU data centers claiming 100% renewable power rely on problematic Guarantees of Origin certificates, obscuring actual consumption patterns. This creates an 'efficiency trap' for investors who must probe beyond headline KPIs like PUE and WUE to assess true value, factoring in asset age and retrofit potential. Minimum Performance Standards testing begins, with new rules on hourly energy matching and water usage likely to reshape the sector's CAPEX and OPEX dynamics.