Power Usage Effectiveness (PUE)

Power Usage Effectiveness (PUE) is the metric used to measure the energy efficiency of a data center or computing facility. It is calculated by dividing the total amount of energy consumed by the data center (including IT equipment and supporting infrastructure) by the energy consumed by the IT equipment alone. (See Data Center Consolidation.)

The formula for calculating PUE

PUE = Total Facility Energy Consumption / IT Equipment Energy Consumption

“Total Facility Energy Consumption” refers to the combined energy consumed by the entire data center, including cooling systems, lighting, power distribution, backup generators, and other supporting infrastructure.

“IT Equipment Energy Consumption” represents the energy used specifically by the IT servers, storage devices, networking equipment, and other computing hardware.

The purpose of the Power Usage Effectiveness metric

The purpose of PUE is to provide insight into the efficiency of a data center’s power usage. A lower PUE value indicates higher energy efficiency because it means a larger proportion of the total energy consumption is used directly by the IT equipment rather than being allocated to supporting infrastructure.

A PUE of 1.0 represents a hypothetical ideal state where all the energy consumed is used exclusively by the IT equipment, with no additional energy needed for cooling or other infrastructure. In practice, achieving a PUE of exactly 1.0 is extremely challenging, and most data centers typically have PUE values above 1.0.

Data center strategies to reduce PUE and improve efficiency

  • Efficient Cooling Systems: Implementing energy-efficient cooling technologies, such as hot and cold aisle containment, precision cooling, or free cooling, to optimize cooling efficiency and reduce energy consumption.
  • Virtualization and Consolidation: Using virtualization technologies to consolidate servers and optimize resource utilization, thereby reducing the overall power requirements of the IT equipment.
  • Energy Management and Monitoring: Implementing energy management systems and monitoring tools to track and optimize energy usage, identify areas of inefficiency, and make data-driven decisions for improvement.
  • Efficient Power Distribution: Employing efficient power distribution systems, such as uninterruptible power supplies (UPS) with high-efficiency ratings, to minimize power losses and increase energy efficiency.
  • Renewable Energy Sources: Incorporating renewable energy sources, such as solar or wind power, into the data center’s energy mix to reduce reliance on fossil fuels and lower the environmental impact.

PUE is just one metric to evaluate data center energy efficiency. Additional factors like water usage efficiency (WUE) and carbon usage effectiveness (CUE) may also be considered for a comprehensive assessment of environmental impact and resource efficiency.

Data Management and Sustainability

In early 2022 supply chain challenges and sustainability were grabbing headlines: See this post for coverage. The focus on improving energy efficiency and reducing PUE has become increasingly important as pressures mount to consolidate data centers, accelerate cloud migration and reduce data storage costs, but to reduce the overall carbon footprint and contribute to sustainable IT operations.

Komprise cofounder and COO Krishna Subramanian published this article: Sustainable data management and the future of green business. Here is how she summarized the importance of unstructured data management to sustainability in the enterprise:

A lesser-known concept relates to managing data itself more efficiently. Most organizations have hundreds of terabytes of data, if not petabytes, which can be managed more efficiently and even deleted but are hidden and/or not understood well enough to manage appropriately. In most businesses, 70% of the cost of data is not in storage but in data protection and management. Creating multiple backup and DR copies of rarely used cold data is inefficient and costly, not to mention its environmental impact. Furthermore, storing obsolete “zombie data” on expensive on-premises hardware (or even, cloud file storage, which is the highest cost tier for cloud storage), doesn’t make sage economic sense and consumes the most energy resources.

The recommendations for achieving sustainable data management in the article are:

  1. Understand your unstructured data
  2. Automate data actions by policy
  3. Work with data owners and key stakeholders

Read the article.


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