ENTRA: Better software cuts computer energy use

An EU research project is developing tools to help software engineers create energy-efficient code, which could reduce electricity consumption at data centres by up to 50% and improve battery life in smart devices. As the demand for computing power increases exponentially, software applications will need to be designed in an energy-efficient way to allow smaller batteries to be charged less frequently.

Until now the target for energy savings by computers has been the hardware. But hardware is only part of the story. Even with energy-efficient hardware, much of the potential for energy savings is wasted by the drain that inefficient software places on systems.

The ENTRA project has come up with an experimental software prototype based on programming semantics that tells programmers how much energy will be consumed as a result of the code they are writing. The ENTRA tool runs alongside the program and, through code analysis and energy modelling, shows how much the code is going to cost the computer in terms of energy use, and what the impact of design decisions on energy use will be.

The ENTRA tool shows energy use in terms of Watts (power consumption) or in absolute energy requirements (the energy needed to finish the task) depending on the speed of the processor (GHz). Rather than having to wait until the program is installed and running on a machine and then measuring its energy (often too late to do anything about it), the programmer gets an early picture from the energy predictions in the code.

With an eye on meeting these challenges, the ENTRA prototype is being tested on three typical energy-hungry components: real-time audio processing, robot and motor control, and real-time networking. The software defining them is being run on hardware at XMOS, a semiconductor company in Bristol, the United Kingdom, which produces for the automotive, computing and games industries. Researchers in the project are seeing in these case studies that energy savings could be at least 20-50 percent, e.g. by compacting programs, and optimizing timing of operations to permit lower processor speeds.

XMOS plans to add ENTRA components for energy optimization into its tool-chain. The ENTRA results are also being exposed to internationally leading companies such as ARM and ST Microelectronics, and world leading academics in energy-efficient computing at the EACO (Energy Aware COmputing) workshops.

The ENTRA project, consisting of 4 partners in Denmark, the UK and Spain, began in October 2012, ends on 30 September 2015, and receives FP7 funding of 2.1 million euros.

Detailed information about the ENTRA project can be found here: