Low latency mode on or off

Hi, would you like to ask whether low latency mode in Nvidia settings is on or off?

PC:
6700k（4.5G)
Nvidia 970
32G RAM (47.6ns 3333Mhz)

Best FPS—120
Aver FPS—75

I need more help setting it up

1 LLM on + vsync lock
2 LLM off + vsync off or fast
3 LLM on + vsync off or fast

LLM Ultra seems to seriously affect CPU performance, please let me know if you know.