The Uptime Institute’s analysis of data centre energy efficiency trends over the past decade, supported by detailed power usage data from over 300 data centers, shows that significant improvements have been made. However, in the report ‘Beyond PUE: Tackling IT’s Wasted Terawatts’, analysis also shows that substantial energy reduction opportunities still remain untapped. While gains in mechanical and electrical efficiency have stalled over the past few years, it remains that over 65% of the power used by IT in data centers is used to process just 7% of the work, due to aging equipment inefficiencies. But if it is time for operators to pay more attention to IT energy efficiency, they need to do their analysis carefully: the slowdown in Moore’s law is creating new complications.
Key trends and findings include:
- Efforts to improve the energy efficiency of the mechanical and electrical infrastructure of the data centre are now producing only marginal improvements.
- Initiatives that span IT that involve most cultural and inter-disciplinary changes and that require major strategic operational changes are the least-implemented energy efficiency practices.
- In a study of 300 data centres, aging IT kit (older than five years) accounted for 66% of IT energy use but contributed just 7% of the compute capacity.
- All these issues are well-known and can only be resolved by senior management, empowered to make decisions that cross the IT/facilities boundary or drive behaviour among suppliers and clients. An understanding of the sheer scale of the energy savings should encourage executives to address the issues more directly.
- Over the past few years, while processor lithography has stagnated at 14 nanometres, the increase in performance per watt has been accompanied by a steady increase in idle power consumption, perhaps due to the increase in core count to achieve performance gains. This is one reason why the case for hardware refresh for more recent kit has become weaker – servers in real-life deployments tend to spend a substantial part of their time in idle. As such, the increase in idle power may overall offset energy gains from performance.