Do games use multi or single thread only ? I want the highest fps in games without hitting hard productivity of course
It depends upon the game, although it would only be reasonable that newer games use a lot of cores. Single core performance was something notable in the Pentium 4 era and before. Even the fastest single core which may run at 5 or 6 GHz would undoubtedly perform worse in newer games and applications than a Quad core or above. So going way down to single core performance is mostly unnecessary because in today's world most applications use at least 2 cores and anything single core is majorly obsolete and vindictive in terms of performance. So you should definitely always look out for the performance in terms of all cores instead of just a single one.
Let me give you an example. A pizza company has 4 cars and needs to access 4 different addresses to send out pizza.
Now, the 1st car is really fast; the other 3 cars aren't. Would it be possible though for the 1st car to visit all four addresses faster than if all 4 cars had to visit them one after another? One car would visit address one, one address two and so on... If only the 1st car were available it would have to visit address one, then go to address two and no matter how fast it is it would never be able to cover all the addresses the way four cars would.
It's the same with threads and cores.