Systems and methods that allow for dynamic quality of service (QoS) levels for an application processor in a multi-core on-chip system (SoC) in a portable computing device (PCD) are presented. During operation of the PCD an operational load of a co-processor of the SoC is determined, where the co-processor is in communication with an application processor of the SoC. Based on the determined load, the co-processor determines a QoS level required from the application processor. The QoS level is communicated to the application processor. The application processor determines whether it can implement power optimization measures, such as entering into a low power mode (LPM), based at least in part on the dynamically communicated QoS level from the co-processor. The present disclosure provides a cost effective ability to reduce power consumption in PCDs implementing one or more cores or CPUs that are dependent upon the application processor.