Need help config Nvidia that when aircrafts cross clouds, FPS drops rapidly in 1.2.5.

[uboats]

I'm using Nvidia GT750m with the latest driver

 

 

As the title says, when the aircrafts cross clouds, the FPS drops rapidly.

In the game option, I put every low but keep the texture medium and turn the heat blur on

But I do not know how to config the options of Nvidia card.

Can anyone give some suggestions about the nvidia configurations.

 

 

I tried to display the FPS in the game by pressing L/R ctrl + Fn + pause (laptop).

But it does not work.