A system and method for efficient reporting of power usage. A power reporting unit within a processor receives a power consumption number once every sample interval from a power monitor. The power monitor determines a power consumption number based on data corresponding to activity levels of one or more functional blocks within the processor. This data corresponds to each of a number of sampled signals within the one or more functional blocks rather than temperature. Thus, the data is independent of environment temperature variations. An average power consumption number is computed based on received power consumption numbers for a running time interval, wherein the running time interval is larger than the sample interval. This value is conveyed to an external agent, such as a controller for a data center rack system. Responsive to receiving and processing the average power consumption number, the external agent may perform one or more actions. For example, the external agent may cause changes in a cooling system.