1. Good Software Consumes Less Energy Alfonso Fuggetta CEFRIEL Politecnico di Milano, May 8th 2014 1

2. ! The Lightness of Software It is true that software cannot exercise its powers of lightness except through the weight of hardware. But it is software that gives the orders, acting on the outside world and on machines that exist only as functions of the software and evolve so that they can work out ever more complex programs. The second industrial revolution, unlike the rst, does not present us with such crushing images as rolling mills and molten steel, but with bits in a ow of information traveling along circuits in the form of electronic impulses. The iron machines still exist, but they obey the orders of weightless bits. Italo Calvino Lightness, in Six Memos for the New Millennium (1985) 2Good Software Consumes Less Energy Milan, 8th May 2014 3. Does Software Consume Energy? 3Good Software Consumes Less Energy Milan, 8th May 2014 4. Yes 4Good Software Consumes Less Energy Milan, 8th May 2014 5. Of course, energy is consumed by hardware eventually. But hardware is activated and controlled by software. 5Good Software Consumes Less Energy Milan, 8th May 2014 6. Lets See Some Examples 6Good Software Consumes Less Energy Milan, 8th May 2014 7. Searching for tip to save battery on iPhone 7Good Software Consumes Less Energy Milan, 8th May 2014 8. But it is not just a mobile-related issue 8Good Software Consumes Less Energy Milan, 8th May 2014 9. For example, lets consider Internet of Things 9Good Software Consumes Less Energy Milan, 8th May 2014 10. Good Software Consumes Less Energy Milan, 8th May 2014 11. And what is nowadays a router or a switcher? 11Good Software Consumes Less Energy Milan, 8th May 2014 12. A computer running software Better, software controlling some circuits ! (think about Software Dened Netwoking) 12Good Software Consumes Less Energy Milan, 8th May 2014 13. Where and How Software Makes Hardware Consume More Energy? 13Good Software Consumes Less Energy Milan, 8th May 2014 14. Hardware OS & Compilers Sw Architectures Application Logic Instructions (CPU, math coprocessor, ) Disks Antennas Screens Buses Sensors (motion, location, ) Other peripherals 14 Memory Management Caching Code Optimization Location & Motion Control Code Mobility Screen Usage App Updates Client-Server Architectures P2P Logic Code Mobility Cloud-based Architectures -SAAS -PAAS -IAAS Algorithms Busy Loops Frequency of Data Refresh Localization and Motion Tracking Push Notications Multimedia Apps Consumers Behavior 15. Software Engineering Research: some examples from next ICSE (June 2014) 15Good Software Consumes Less Energy Milan, 8th May 2014 16. Better Usage of Hardware Resources Good Software Consumes Less Energy Milan, 8th May 2014 17. Infrastructure OptimizationGood Software Consumes Less Energy Milan, 8th May 2014 18. Design MethodGood Software Consumes Less Energy Milan, 8th May 2014 19. A Lot of (Interesting) Research Work Integration of multiple technologies and domains (Hardware, Networking, Software Architecture, Application & Service Logic, ) Holistic approach to system and application design The role of users and of ethnography 19Good Software Consumes Less Energy Milan, 8th May 2014 20. A Lot of (Useful) Innovation Work Transform ideas and concepts into products that do meet users expectations and needs Provide concrete and effective solutions and not just a theoretical or symbolic contribution 20Good Software Consumes Less Energy Milan, 8th May 2014 21. Thank you! 21Good Software Consumes Less Energy Milan, 8th May 2014