AMD has just unveiled Frame Latency Meter (FLM), an open-source Windows utility designed to measure the response time of games based on mouse movements. This tool is specifically designed for advanced gamers, power users, and game developers who are focused on optimizing whole-system latency or reducing input lag. FLM measures the time it takes for a mouse movement to translate into a new frame on the screen, offering detailed insights into system performance.
Frame latency measurements, commonly used to approximate input lag, traditionally involved a high-speed camera, a mouse, and an FPS game with a visible muzzle flash. The camera would capture the moment the mouse was clicked, and you would count the frames until the muzzle flash or other on-screen reaction appeared. FLM eliminates the need for such specialized equipment and works seamlessly with any AMD, Nvidia, or Intel GPU that supports DirectX 11 or newer.
AMD GPUs leverage the Advanced Media Framework (AMF) codec for data capture, while other GPUs utilize the DirectX Graphics Infrastructure (DXGI) codec. FLM generates comprehensive latency and effective frame-rate statistics, which can be exported to CSV files for further analysis. To achieve precise latency measurements, FLM continuously captures frames, comparing each frame to the previous one within a selected region. It then triggers a mouse movement event using standard Windows functionality and waits for the frame contents to change. The time between the mouse movement and the detected frame change is recorded as the latency. For enhanced accuracy, 16 latency measurements are averaged per row, and users can choose to average even more measurements for greater precision.
FLM eliminates the reliance on muzzle flashes for latency measurements, enabling quick, repeated measurements without ammo limitations. This allows for the autonomous collection of unlimited samples, leading to higher accuracy. The software also offers a degree of customization, allowing users to measure latency based on either mouse movements or clicks. Users can specify frame capture regions and choose between small samples, continuous accumulation, or a constant meter for measurements. Additionally, FLM supports frame generation technology, although compatibility with all games supporting the latest FSR 3 or DLSS 3 remains unclear.
FLM is available as a free download for Windows 10 and 11 users through GPU Open or the official GitHub repository.
