 - Power usage effectiveness (PUE) is a metric used to determine the energy efficiency of a data center. PUE is determined by dividing the amount of power entering a data center by the power used to run the computer infrastructure within it. PUE is therefore expressed as a ratio, with overall efficiency improving as the quotient decreases toward 1. PUE was created by members of the Green Grid, an industry group focused on data center energy efficiency. Data center infrastructure efficiency (DCIE) is the reciprocal of PUE and is expressed as a percentage that improves as it approaches 100%.
How to Determine PUE
1. Take a measurement of energy use at or near the facility's utility meter. If the data center is in a mixed-use facility or office building, take a measurement only at the meter that is powering the data center. If it is not on a separate utility meter, estimate the amount of power being consumed by the non-data center portion of the building and remove it from the equation.
2. Measure the IT equipment load after power conversion, switching, and conditioning is completed. According to The Green Grid, the most useful measurement point is at the output of the computer room power distribution units (PDUs). This measurement should represent the total power delivered to the server racks in the data center.
According to the Uptime Institute, the typical data center has an average PUE of 2.5. This means that for every 2.5 watts in at the utility meter, only one watt is delivered out to the IT load. Uptime estimates most facilities could achieve 1.6 PUE using the most efficient equipment and best practices.
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Learn more about Data center backup power and power distribution |
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| Right-sizing is the key to energy-efficient data centers: Energy efficiency - the monkey on every data center manager's back. We spoke to APC's Chief Technical Officer, Neil Rasmussen about energy efficiency strategies in the data center. |
| EPA eyes Energy Star label for servers: The EPA may include servers in its Energy Star program and will study data center energy consumption in the coming months. |
| Data Center Library: Enterprise Data Center Design and Methodology: A review of Enterprise Data Center Design and Methodology by Sun Microsystems Inc.'s Enterprise Architect Rob Snevely. |
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Bob McFarlane: Blogs and more: Expert Bob McFarlane recently hosted a blog that tackled the full array of problems that face anyone managing a data center's physical environment. The best of the blog is here. |
| The Price of Power: Traditionally, the price of power fell was a problem for facilities management. But as both the price and demand for power skyrocket, it's a problem IT can no longer ignore. |
| Power: Check out all the best power related content SearchDataCenter has in one easy location--don't get zapped for being out of the circuit. |
| Power Playbook: This Playbook directs you to the best sources on protecting yourself against outages, testing your UPS, to a guide to fault tolerant power compliance specs. |
| CONTRIBUTORS: |
Mark Fontecchio |
| LAST UPDATED: |
11 Jan 2010
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