Practical energy saving and power-workload proportionality in a campus environment

This paper reports the results of a study that aims to identify where it would be possible to reduce the energy consumption of IT equipment at BT's (British Telecom) site at Adastral Park in the UK. We studied a small sample of the equipment (routers, switches and servers) which were owned by the research team. The paper identifies practical steps that system administrators can take to reduce their power use and achieve Power-Workload Proportional (PWP) IT. We propose a model to calculate the average power consumption of servers and network devices, and propose a new metric "Waste" that measures how "green" a device is by calculating wasted energy consumption per performance/throughput e.g. the "Waste" per Gbps for the network and "Waste" per GHz for the server. Based on this study, we estimate that it would be possible today to save 38.6% of server energy consumption and up to 19.9% of network equipment energy consumption at the BT site