PUE & DCiE Calculator

PUE and DCiE are used to benchmark a data centre's energy efficiency and gives a simple metric to track and illustrate energy allocation.

Introduction

By utilising PUE and DCiE metrics in your data centres you put yourself in a better position to monitor, understand and improve your energy efficiency. Over time you are able to see the positive impacts of hardware upgrades and track causes of negative impacts on your data centres.

Within a data centre power and cooling account for the two biggest issues when it comes to bringing costs down as well as allowing for future expansion. By bringing these two factors under control it allows you to run a more efficient data centre, allowing you to better manage increased demand for computing power, storage or network expansion while maintaining low energy costs and a reduced cost of ownership.

Where to start

Use the below form to calculate what your installation's PUE and DCiE metrics are.

Enter in the total amount of energy your facility is using (kw)

kw

Enter the total amount of energy your IT equipment is using (kw)

kw

Your score

0/100

Consistency

Now that you have an idea on what your PUE and/or DCiE score is for your data centre it's important to note that it's not a true representation of the efficiency of your installation. Measurements need to be taken over time in order to get a more accurate score and better representation of energy consumption within your data centre.

The EU Code of Conduct on Data Centre Energy Efficiency lays out guidelines for the best way to approach monitoring your data centre:

  1. Periodic manual readings - Manually note readings of meters within your data centre at regular intervals and ideally at peak load.
  2. Automated daily readings - To get more accurate and effective readings it is advised to automate the monitoring and metering process to at least once a day.
  3. Automated hourly readings - Automated hourly readings enable the ability to assess how IT energy varies throughout the workload and gives an even more accurate and effective results than all above options.
Automated readings

Further to the benefit of accurate measurements from automated readings your company can benefit in other ways. Through the use of the metrics paired with strategic planning to improve performance companies have seen benefits such as:

  • Ability to demonstrate compliance with current statutory and regulatory requirements.
  • Increase in leadership involvement and engagement of employees.
  • Improve company reputation with strategic communication with the data to endorse claims.
  • Provide a competitive and finanacial advantage through improved efficiencies and reduced running costs.

If you would like Spook to help your company experience these benefits then please contact us.

Definitions
PUE

PUE is Power Usage Effectiveness and is the ratio of how efficiently a computer data centre uses energy. The ratio is calculated between the total amount of energy used by a data centre to the total amount of energy used to power IT equipment.

Measurements can range from 1.0 to infinity where 1.0 is 100% efficiency (i.e. all power used by IT equipment only).

PUE = total facility power / IT equipment power
DCiE

DCiE is Datacentre Infrastructure Efficiency and represents the percentage (%) of energy used to power IT equipment from the total amount of energy used by a data centre.

DCiE = ( IT equipment power / total facility power ) x 100
IT Equipment Energy

IT equipment is defined as the equipment that is used to manage, process, store or route data within the data centre.

In this context it refers to all of the IT hardware within the data centre such as servers, computers, storage and networking equipment. It also includes supplimental equipment such as KVM switches, monitors, workstations and laptops used within the building.

To get the most accurate result it is advised to measure the output of the computer room power distribution units (PDUs) that are directly feeding computer equipment racks.

Total Facility Energy

Total facility energy refers to everything that supports the IT equipment load such as:

  • Power delivery components - e.g. UPSs, switch gear, generators, PDUs, batteries and distribution losses external to the IT equipment.
  • Cooling system components - e.g. chillers, computer room air conditioning units (CRACs), direct expansion air handler (DX) units, pumps and cooling towers.
  • Other miscellaneous components - e.g. data centre lighting.

To get the most accurate result it is advised to measure from meters that only feed the data centre if possible to avoid including unwanted values. If this is not possible a calculation can be made on power feeds to the room itself or estimate the amount of power being consumed by the non-data centre offices. This will of course introduce errors and inaccuracy into the final result.