Green Methodologies in Desktop-Grid

Desktop-Grids have been around since the very early days of Grid computing, scaling into the millions of PCs, well established as regular distributed computing infrastructure for many research projects. Desktop-Grids collect CPU cycles from PCs contributed by donors, by volunteers who are willing to support science and research. This paper focusses on the energy efficiency aspects of Desktop Grid computing: the Green Desktop Grid, as a task of the EU-FP7 DEGISCO project. The key advantage of Desktop-Grids with regards to Green-IT over service Grids and data centres based on clusters of servers is the minimal heat density. Compute Clusters without energy intensive air-condition would run into thermal disaster within minutes. PCs participating in Desktop-Grids usually do not make use of any air-condition. We will have a closer look on several aspects of energy consumption and computational performance in Desktop-Grids describing several distinct Green Methodologies to optimize compute unit specific energy consumption.