Dynamic power saving in fat-tree interconnection networks using on/off links
Marina Alonso, Salvador Coll, Juan-Miguel Martínez, Vicente Santonja, Pedro López, José F. Duato · 2006
Current trends in high-performance parallel computers show that fat-tree interconnection networks are one of the most popular topologies. The particular characteristics of this topology, that provide multiple alternative paths for each source/destination pair, make it an excellent candi-date for applying power consumption reduction techniques. Such techniques are being increasingly applied in computer systems and the interconnection network is not an excep-tion, since its contribution to the system power budget is not negligible. In this paper, we present a mechanism that dynamically switches on and off network links as a function of traffic. The mechanism is designed to guarantee network connectivity, according to the underlying routing algorithm. In this way, the default routing algorithm can be used re-gardless of the power saving actions taken, thus simplifying router design. Our simulation results show that significant network power consumption reductions can be obtained at no cost. Latency remains the same although the number of operating network links is dynamically adjusted. 1