Systems and methods for measuring the effectiveness of a workload predictor operative on a mobile device are disclosed. A load manager includes a workload predictor, a sensor, an error generator and a controller. The workload predictor generates an estimate of the workload on a processor core operative on the mobile device. The sensor generates a measure of the actual workload on the processor core. The error generator receives the estimate of the workload and the measure of the actual workload on the processor core and generates an error signal. The controller receives the error signal and determines the effectiveness of the workload predictor as a function of the error signal over time.