Software Energy Footprint Lab

IT consumes energy. Globally the IT sector is responsible for emitting more CO2 equivalents than the aviation industry. The software on IT systems puts the hardware to work. Thereby, the root cause of IT energy consumption lies in the software that commands the hardware to start processing. Recent advances in hardware and data center technologies show large increases in energy efficiency. However, given the explosive demand for processing power, another strategy has to be taken to keep the use of IT systems within tolerable energy consumption limits. Therefore, the Software Energy Footprint Lab (SEFLab) was founded in February 2012 as a joined effort between IT certifier the Software Improvement Group (SIG) and the CleanTech research programme of the Amsterdam University of Applied Science (Hogeschool van Amsterdam, HvA).

In the SEFLab collaborative research PROJECTS between software specialists from the SIG, electrical engineers from the HvA and various industry PARTNERS study the influence of software on the energy consumption of computers.

Highly accurate energy consumption measurements are taken at high frequencies at various hardware components within servers. The measurements are related to software executed on the server, allowing for energy efficiency comparisons between different software applications, different software architecture design or different source code.

Aims & objectives

The SEFLab aims to reduce this environmental impact of IT by studying the relation between software and the hardware it runs on resulting in:

  • a model to help data centers and IT departments predict and reduce their server energy consumption;
  • guidelines and tools for software developers to help them implement green coding principles;
  • an energy label for software applications to help end-users make informed purchase decisions.


Fig 1. SEFLab measurement setup

Fig 1. SEFLab measurement setup

Currently the lab has two servers equipped with sensors that can be used for testing. Figure 1 shows a schematic of the measurement setup. Server components that are individually measured include the two CPU’s, hard drives, memory, main board and fans. A highly accurate data-acquisition system measures the voltage drop over sense resistors placed within the power lines of the server. From these measurements voltage, current, and power use are calculated.

A load scenario is constructed that stresses the server with different loads generated by the software running on the server. Performance indicators of the operating system like CPU load, network traffic, and memory use are gathered throughout the experiments. After synchronization and analysis of the different data sources, the different load scenarios can be compared on energy consumption. An example of power measurements of two CPUs, and comparison of four load scenarios are shown in figure 2 and 3.

Fig 3. Scenario comparison power consumption

Fig 3. Scenario comparison power consumption

Fig 2. CPU power measurement

Fig 2. CPU power measurement


There are multiple ways in which you or your organization can collaborate with the SEFLab.

Research project:

  • Software developers. As a software developer you know best which design choices you face in the development of your software. Together we can test which consequences these choices have in terms of energy consumption and/or CO2 equivalent footprint.
  • IT users. Your organization might have the choice between various software applications with similar functionality but different processing capacity requirements. Together we can test how your choice for a certain application influences the amount of rack space you need to rent or the amount of servers your IT department needs to purchase, or the amount energy or CO2 equivalent you can save.
  • Researchers. We are happy to share our knowledge and measurement setups to support your research or start collaborative research projects.
  • Students. We are always looking for motivated students to join the lab as an intern, as a student assistant, or for doing bachelor or master theses research at the SEFlab. Fields of study that we are looking for (but not limited to): electrical engineering, computer science, informatics, mechanical engineering, and industrial engineering.

Sounding board: Introducing an energy label for software applications requires broad support from industry stakeholders. We would like to invite these stakeholders to join the discussion on how this label should take shape.

Hardware sponsor: We do not have the funds to purchase the newest hardware to rig with sensors. We already have a list of sponsors that donated computer hardware to our lab and would be happy to keep our lab up-to-date with new computers to perform measurements on.