<p>In recent years, the drive for ever increasing energy efficiency has intensified. The main driving forces behind this development are the increased innovation and adoption of mobile battery powered devices, increasing energy costs, environmental concerns, and strive for denser systems.</p><p>This work is meant to serve as a foundation for exploration of energy conscious software. We present an overview of previous work and a background to energy concerns from a software perspective. In addition, we describe and test a few methods for decreasing energy consumption with emphasis on using software parallelism. The experiments are conducted using both a simulation environment and real hardware. Finally, a method for measuring energy consumption on a hardware platform is described.</p><p>We conclude that energy conscious software is very dependent on what hardware energy saving features, such as frequency scaling and power management, are available. If the software has a lot of unnecessary, or overcomplicated, work, the energy consumption can be lowered to some extent by optimizing the software and reducing the overhead. If the hardware provides software-controllable energy features, the energy consumption can be lowered dramatically.</p><p>For suitable workloads, using parallelism and multi-core technologies seem very promising for producing low power software. Realizing this potential requires a very flexible hardware platform. Most important is to have fine grained control over power management, and voltage and frequency scaling, preferably on a per core basis.</p>

In recent years, the drive for ever increasing energy efficiency has intensified. The main driving forces behind this development are the increased innovation and adoption of mobile battery powered devices, increasing energy costs, environmental concerns, and strive for denser systems. This work is meant to serve as a foundation for exploration of energy conscious software. We present an overview of previous work and a background to energy concerns from a software perspective. In addition, we describe and test a few methods for decreasing energy consumption with emphasis on using software parallelism. The experiments are conducted using both a simulation environment and real hardware. Finally, a method for measuring energy consumption on a hardware platform is described. We conclude that energy conscious software is very dependent on what hardware energy saving features, such as frequency scaling and power management, are available. If the software has a lot of unnecessary, or overcomplicated, work, the energy consumption can be lowered to some extent by optimizing the software and reducing the overhead. If the hardware provides software-controllable energy features, the energy consumption can be lowered dramatically. For suitable workloads, using parallelism and multi-core technologies seem very promising for producing low power software. Realizing this potential requires a very flexible hardware platform. Most important is to have fine grained control over power management, and voltage and frequency scaling, preferably on a per core basis.