Abstract: Energy and power efficiency are becoming important topics within the graphics community. In this paper, we present a simple, straightforward method for measuring per-frame energy consumption of real-time graphics workloads. The method is non-invasive, meaning that source code is not needed, which makes it possible to measure on a much wider range of applications. We also discuss certain behaviors of the measured platforms that can affect energy measurements, e.g., what happens when calling glFinish(), which ensures that all issued graphics commands are finished executing. Measurements are done both on a smartphone and on CPUs with integrated graphics processors.