The quest for energy efficiency has growing importance in high performance many-core systems. However, in current practices, the power slacks,which are the differences observed between the input power budget and the actual power consumed in the many-core systems, are typically ignored, thus leading to poor energy efficiency. In this paper, we propose a scheme to effectively power the on-chip communications by exploiting the available power slack that is totally wasted in current many-core systems. As so, the demand for extra energy from external power sources(e.g.,batteries) is minimized, which helps improve the overall energy efficiency. In essence, the power slack is stored at each node and the proposed routing algorithm uses a dynamic programming network to find the globally optimal path, along which the total energy stored on the nodes is the maximum. Experimental results have confirmed that the proposed scheme, with low hardware overhead, can reduce latency and extra energy consumption by 44% and 48%, respectively, compared with the two competing routing methods.Index Terms ? Adaptive routing, dynamic The quest for energy efficiency has growing importance in high performance many-core systems. However, in current practices, the power slacks, which are the differences observed between the input power budget and the actual power consumed in the many-core systems, typically ignored, thus leading to poor energy efficiency. In this paper, we propose a scheme to effectively power the on-chip communications by exploiting the available power slack that was totally wasted in current many-core systems. As so, the demand for extra energy from external power sources (eg, batteries) is minimized, which helps able the overall energy efficiency. which can helps improve the overall energy efficiency. the total energy stored on the nodes is the maximum. Experimental results have confirmed that the proposed scheme, with low hardware overhead, can reduce latency and extra energy consum ption by 44% and 48%, respectively, compared with the two competing routing methods.Index Terms? Adaptive routing, dynamic