Both Intel and AMD invented a methodology that can select the fastest core to be the 'favored core'. However, as with anything, Windows does not recognize that. Basically an application could end up at the slowest core.
That is going to change with a pending 'big' Windows update as Microsoft will be including favored core awareness into the OS, and that can speed up single-threaded applications up-to 15%. For Intel Turbo Boost Max Technology 3.0, an operating system will use information stored in the CPU to identify which cores are the fastest and then prioritize them, Intel, says "delivers more than 15% better single-threaded performance". "A CPU may have multiple “favored” cores (logical processors of the highest available scheduling class). To provide better performance and reliability, we have implemented a rotation policy that distributes work more fairly among these favored cores."
For AMD, Microsoft already included an optimization in the last 1903 update, we're not certain if the 19H2 update will have an actual effect as it already might be supported.