Low framerate (fps drops)

[Povizdlo]

So I tried everything. From lowering all the settings down to turning them to maximum.
Tried to put different addons, yet still the game is lagging. Even on starting screen, there is like 5-15 fps.
Deleteing and re-installing didn't help either. V-sync - no effect for framerate.
Everything was normal untill 3 days before this post. My computer equipment is the same as before, In every map that I start to play fps drops up to 6-10. There are also big drops in fps if I turn in any directions.
I found a guy on reddit with similar probleme, but this guy just gave up this game.
Is there a way to play it with normal fps ever again?

[:::... FulVal [LMHT] ...:::]

This game is using only the first core by default...
try to open task manager when SS:R is opened, go to .exe process and enable all other cores

[Povizdlo]

I now figured it out. You need to open task manager for it to work.