Input responsiveness should be evaluated independently from FPS.
Validation should cover the complete pipeline:
Controller Input → Game Simulation → Rendering → Frame Presentation → Display
Testing should determine whether frame-time spikes, simulation delays, or rendering bottlenecks increase perceived controller latency.
Recommended metrics
Input-to-photon latency
Input consistency during frame-time spikes
Controller response during heavy CPU/GPU load
ADS response consistency
Sprint/jump/melee input response
Vehicle control responsiveness
The objective should be consistent responsiveness, not simply a high FPS counter.