How it works
Frame pacing concerns the spacing between displayed frames. At a steady 60 FPS, an evenly delivered sequence is roughly one frame every 16.7 milliseconds. An average of 60 FPS can also include short bursts and long pauses, which produce a different visual experience despite the same average number.
Important differences and limits
Rendering time, presentation timing and display refresh timing are related but not identical measurements. Loading, compilation, background tasks and an unstable frame limiter can produce irregular delivery. A monitor with adaptive refresh can reduce some display mismatches, but cannot make a long unfinished frame arrive earlier.
A useful practical check
Use a frame-time graph while following a repeatable path through the game. Look for recurring spikes and changes after a frame cap or settings adjustment. Test a cap the system can sustain, not merely the highest average FPS. Judge the result in motion and check whether responsiveness remains comfortable.
An example in practice
For example, alternating short frames with noticeably long ones can keep the average attractive while movement looks uneven. A slightly lower sustainable cap may feel better. Confirm that result by watching the same camera movement and the timing graph, not by reading only the average. Capture the same interval for every run, since mixing a brief quiet scene with a longer demanding route distorts the comparison.