Minecraft with shader only 70/80 FPS?

I have a Ryzen 5 3600 and a Gtx 1660 Super. I activated G-sync to use the full 144hz, only with Shader (BSL) I only achieve 70/80 fps, although it should be significantly more, see video:

Is G-Sync set incorrectly? Or what could it be?

Did you also set 12 chunks?

And are you in an empty bucket world?

Do you mean empty world, flat country? I switched from 14 to 12 chunks, I have 90/100 fps.

No, just like in the video, but undeveloped.

The shader also has different quality levels.

I'm in an undeveloped world, 90/100 fps

There's nothing more to come with the 1660 because the shader only runs over the graphics card

Thanks anyway!