Press Releases

Power Assure CTO Provides Insights into Data Center Energy Efficiency Rating Systems

August 23
08:58 2011

Hosting NewsSanta Clara, CA – Companies are now paying very close attention to power consumption throughout their data centers. To support this growing need, the industry has created both the metrics and tools required to measure and manage power utilization effectively.

Clemens Pfeiffer, CTO of Power Assure, Inc., has outlined the various rating systems available, and recommends how each can be used to improve energy efficiency throughout any data center.

Data center energy efficiency rating systems include:

Power Usage Effectiveness (PUE) rating system. PUE, created by the Green Grid, is the ratio of total power consumed to the power used by the IT equipment. The real challenge exists in getting accurate measurements for Total Facility Power and IT Equipment Power, especially if the data center is part of a mixed-use building.

Data Center Infrastructure Efficiency (DCiE) rating. DCiE, is the reciprocal of PUE: the ratio of the power used by the IT equipment to the total power consumed. Standards like PUE and DCiE have brought awareness to the importance of measuring data center efficiency, but they do not provide any criteria to show incremental improvements in efficiency over time, nor do they monitor the effective use of the power supplied.
To remedy this shortcoming, both McKinsey and Gartner have created broader rating systems that account for IT energy efficiency.

Corporate Average Datacenter Efficiency (CADE). Developed by McKinsey, CADE helps organizations better visualize and manage the efficiency, capacity, and performance of their data centers by addressing the biggest source of waste in data centers today: poor server utilization.

Power to Performance Effectiveness (PPE). Developed by Gartner, PPE helps identify at the device level where efficiencies could be gained by allowing users to define their own optimal maximum performance levels, and then compare average performance against the optimum.

Organizations routinely replace aging servers to take advantage of the overall performance improvements that generally track according to Moore’s Law. Determining the optimal time to refresh which servers, however, is not so straightforward.

EnergyStar rating system. To help IT managers more accurately determine when to refresh servers, the EPA created an EnergyStar rating system. But EnergyStar has a fundamental flaw similar to the one found in the PUE and DCiE rating systems: It ignores the transactional efficiency of servers by focusing instead on just the power supply. In addition, EnergyStar simply gives its top ranking to the ?best 25% of servers each year, and ignores any improvements made over time.

PAR4 rating. Power Assure partnered with Underwriters Laboratories to develop PAR4, a highly accurate method for determining both absolute and normalized (over time) energy efficiency ratings for both new and existing equipment on a transaction-per-second per-watt basis. The 4 in PAR4 indicates that four separate measurements are made: power-on spike, wave form, boot cycle and 100% load. These measurements are then used to determine idle and peak power consumption, as well as transactions-per-second-per -watt and other useful annualized ratings.

“Power consumption in the data center is on the rise as demand for Internet services like music and video downloads increase and the number of servers needed to deliver this data multiply and age,” said Pfeiffer.  “Visibility needed to manage operational and design improvements in the data center are spurring the adoption of energy metrics along with Data Center Infrastructure Management (DCIM) software that can establish the power baseline, and can then track improvements using multiple rating systems.”

For more details, a white paper titled, “Combining PUE with other energy efficiency metrics” is available for download here:

About Power Assure
Power Assure is a leading developer of Data Center Infrastructure and Energy Management software for large enterprises, government agencies, and managed service providers. Power Assure’s solutions provide visibility, intelligence, analytics and automation to help CIOs, IT directors, and facilities managers optimize capacity, service levels, and power consumption within and across data centers. Headquartered in Santa Clara, CA, the company is privately held with funding from ABB Technology Ventures, Draper Fisher Jurvetson, Good Energies, Point Judith Capital, and a grant from the Department of Energy. Power Assure partners include ABB, Cisco, Dell, IBM, Intel, Raritan, UL and VMware.

Research, evaluate and learn more about website hosting at

About Author

Providing Web Host News, Discussions, Reviews, Commentary, Interviews and Blog Articles to the FindMyHost, Inc. Network.

Related Articles

Special Offers: