Totally green

Abstract

The environmental impact of servers and datacenters is an important future challenge. System architects have traditionally focused on operational energy as a proxy for designing green servers, but this ignores important environmental implications from server production (materials, manufacturing, etc.). In contrast, this paper argues for a lifecycle focus on the environmental impact of future server designs, to include both operation and production. We present a new methodology to quantify the total environmental impact of system design decisions. Our approach uses the thermodynamic metric of exergy consumption, adapted and validated for use by system architects. Using this methodology, we evaluate the lifecycle impact of several example system designs with environment-friendly optimizations. Our results show that environmental impact from production can be important (around 20% on current servers and growing) and system design choices can reduce this component (by 30--40%). Our results also highlight several, sometimes unexpected, cross-interactions between the environmental impact of production and operation that further motivate a total lifecycle emphasis for future green server designs.