Players often conflate input lag and frame lag. They feel similar but have different causes and different fixes.
Input lag
The time between a physical action (mouse click, key press) and the game registering it. Sources:
- Mouse polling rate and USB interrupt latency
- Mouse acceleration curve (affects perceived responsiveness)
- Game input sampling frequency
- Network latency (for server-authoritative games)
- Display latency (monitor response time + panel lag)
Windows-side fixes: disable pointer precision, remove SmoothMouseXCurve, reduce USB interrupt moderation.
Frame lag
The time between the game rendering a frame and that frame appearing on your display. Sources:
- Render queue depth (how many frames GPU queues ahead)
- DWM composition latency
- Display signal processing
- VSync buffer depth
Windows-side fixes: MaxFrameLatency=1, disable MPO, Low Latency Mode Ultra (NVIDIA), Anti-Lag (AMD).
Why they feel similar
Both make the game feel unresponsive. High input lag means your actions register late. High frame lag means you see the result of your actions late. On high-latency connections, both are present simultaneously.
Measuring separately
- Input lag: measure with a high-speed camera filming your mouse click and the on-screen reaction simultaneously
- Frame lag: measure with FrameView or RTSS showing frame times and GPU render latency
Fixing both requires different registry changes. IzanagiOP's Trajectory Pack addresses input lag, Frame Pack addresses frame lag. https://terweb.lt/
