CPU flame graphs are a powerful visualization tool for profiling CPU usage, but they are often applied at the system level. This article adapts them to the granularity of a single logical frame, common in game engines and real-time simulations. By capturing stack traces at frame boundaries and aggregating them per frame, developers can see exactly which functions consume the most time within each frame cycle. The method helps identify unexpected hotspots, such as physics calculations, AI logic, or rendering overhead, that degrade frame rate consistency. Unlike traditional profilers that show average CPU load, this frame-level flame graph reveals per-frame variance and jitter. The technique is particularly useful for debugging frame drops and ensuring smooth 60fps or 120fps performance. It requires minimal tooling—just a sampling profiler and a script to align samples with frame markers. The article provides a step-by-step guide to generating these graphs, interpreting the results, and applying fixes. For developers working on latency-sensitive applications, this approach offers a clear, actionable path to optimization.
A technique for using CPU flame graphs to break down logical frame time into hotspots, aiding performance optimization in real-time applications.