So i solved the really low FPS problem by changing Nvidia Driver Version. Im assuming version 416 of the driver is the cause, what driver are you using for smooth FNV gameplay? Im very sure its not a mod related... Cause i havent added a thing

I use the last version,driver can be bad and  kill fps but normaly the problem whit fps is enb/textures mod or vsyng any way thanks for posting ur experiencie and remember the last driver version will be better for ur other games if u need to reinstall driver use ddu

DDU link https://www.guru3d.com/files-details/display-driver-uninstaller-download.html

Thanks for the info, i think a clean install will help. Ill try it out and let everyone know if it works

@blahblahblah You're welcome, happy to help!!!