Resumen
Energy consumption is one of the main limiting factors for designing and deploying ultrascale systems. Therefore, this paper presents challenges and trends associated with energy efficiency for ultrascale systems based on current activities of the working group on "Energy Efficiency" in the European COST Action Nesus IC1305. The analysis contains major areas that are related to studies of energy efficiency in ultrascale systems: heterogeneous and low power hardware architectures, power monitoring at large scale, modeling and simulation of ultrascale systems, energy-aware scheduling and resource management, and energy-efficient application design.