Throttling-Based Resource Management in High Performance Multithreaded Architectures

Up to now, the power problems which could be caused by the huge amount of hardware resources present in modern systems have not been a primary concern. More recently, however, power consumption has begun limiting the number of resources which can be safely integrated into a single package, lest the heat dissipation exceed physical limits (before actual package meltdown). At the same time, new architectural techniques such as simultaneous multithreading (SMT), whose goal it is to efficiently use the resources of a superscalar machine without introducing excessive additional control overhead, have appeared on the scene. In this paper, we present a new resource management scheme which enables an efficient low power mode in SMT architectures. The proposed scheme is based on a modified pipeline throttling technique which introduces a throttling point at the last stage of the processor pipeline in order to reduce power consumption. We demonstrate that resource utilization plays an important role in efficient power management and that our strategy can significantly improve performance in the power-saving mode. Since the proposed resource management scheme tests the processor condition cycle by cycle, we evaluate its performance by setting a target IPC as one sort of immediate power measure. Our analysis shows that an SMT processor with our dynamic resource management scheme can yield significantly higher overall performance