I'm having trouble with Multi-Frame Generation on an RTX 4090 using one of the mods that enables NVIDIA's MFG features on 4000-series cards. Without frame generation, I get about 80 base FPS. With 2x frame generation, I see around 60 base FPS uncapped, but enabling Reflex, RTSS, or VSync at 120 FPS causes the base rate to drop to about 30 FPS. The same thing happens with 3x and 4x MFG: the display may show 120 FPS, but the actual rendered frame rate is only around 30 FPS. This increases input latency and causes visual artifacts near the edges of the screen. Is there a limiter that caps only the generated frames while leaving the base FPS unchanged, or is this expected behavior?
2 Answers
This appears to be expected rather than a configuration mistake. With 4x generation and a 120 FPS limit, the system only needs 30 rendered frames per second because the other 90 frames are generated. The displayed FPS reaches the cap, but the underlying base FPS is necessarily lower.
With a fixed MFG multiplier, the driver can’t generate a fractional number of frames per rendered frame. For example, in 4x mode with a 120 FPS cap, it needs to render 30 real frames and generate three additional frames for each one. So the limiter is working toward 120 total FPS by reducing the base rate to 30 FPS. Dynamic mode may help because it can switch between multipliers to target a frame rate, although it won’t behave like a perfectly strict cap.
That makes sense, although dynamic mode also seems to hold the base rate around 30 FPS for me. I’m using a 120 Hz LG C2, so it sounds like MFG is mainly designed for higher-refresh displays. Regular frame generation didn’t cause this issue with VSync, but the MFG mod does.