• Sentry Software,
    The Only Way :

    • to Monitor the power consumption of all servers and storage devices
    • to Measure (in Watts) the actual energy savings
    • to Report (in kWh) the energy consumed server by server, device by device to charge-back energy costs to application owners
    • to Monitor the temperature in all servers to find the optimal temperature of the data center

Energy Cost Control

1. Understand Energy Consumption in the Server Room

Since reducing energy consumption has become one of the biggest challenges these days, companies around the world are looking are for ways to save energy and reduce costs. The first action of any strategy should to be to understand the current energy usage and to know where and by what specific equipment the energy is used.

Managers, who buy data center equipment, including servers and related hardware, need objective, credible energy performance information.

Facilities in IT Budget

When looking at the global budget of a typical IT department, one cannot avoid noticing that facilities constitute a more and more important share of the overall budget. In fact, recent studies show that it represents 8% of the whole IT budget and this share is growing 20% annually.

Source: McKinsey and UpTimes: breakdown shown is typical of IT intensive businesses, forensic accounting is required to capture all facility costs

Implications of Improved Density

Looking at the technology evolution over the past decade hardly explains how electricity consumption has become such an issue. Faster processors and higher-capacity disks that enable running the same application on ten times less machines should logically consume ten times less energy. Nevertheless, the main reason for which this logical assumption does not apply is that application development and deployment outpaced hardware improvements by large.This implies that, in total, data centers run more servers and other devices than they used to 10 years ago.

In the meantime the power drawn by each server and the heat that it generates has increased substantially. Today, the heat generated by a rack fully loaded with blade servers draws 21 kilowatts of electricity and generates 30 kilowatts of heat. This can explain why many data centers are reaching their capacity limit in terms of power and cooling.

Source : Emerson Network Power/Liebert

World Data Center Electricity Use

The graph below represents the energy consumption of data centers worldwide in billions of kilowatt hours. It makes it obvious to observe that the total number double between 2000 and 2005; which confirms another study by the Environment Protection Agency that states that energy costs to operate data centers have doubled between 2001 and 2006, and will double again before 2011.

Power Usage Effectiveness (P.U.E.) (Source : Koomey 2008)

Power Usage Effectiveness (P.U.E.)

In what the part of electricity dedicated to non-IT operations consists of? The graph below clearly shows the three main elements:

  • Cooling (air conditioning, chillers, etc.), for the biggest part
  • UPS (uninterruptible power supplies)
  • Losses due to voltage transformation

An efficient metric to measure the extra-energy required to power a data center consists in the "P.U.E." (Power Usage Effectiveness); which corresponds to the total facility power divided by the IT equipment power.

The graph highlights how the P.U.E. is distributed among the different elements that consume electricity in a data center.

Next step: EVALUATE »