you need to give more specific information for that claim, what is exactly running in the 8 cores? what is keeping the game from running at 60 fps its the data management, I/O, IA, states , physics, the render time is too long, draw calls , vsync?
and even without clarification your example sounds very reductive and you dont seems to care much for efficiency, cost or power consumption, there are optimisations you can use on consoles that you cannot be sure will be available on PC, for example PS4 dont need to move data betwen different pools like PC that alone saves a lot of time for DMA on Xbox you have the move engines to compensate, on PS4 you will do physics on GPU by default, on PC you will probably run them on CPU or move them to GPU but consider that for the game requirements, if you run them on CPU then the work load is higher in PC compared to a console or maybe you will use a middle ware that handle that, also API overhead is almost non existant on consoles, DX12 and vulkan are there to make much more efficient drawcalls from multiple cpu cores on consoles drawcalls are not a problem while on PC you need generally more CPU power to resolve them faster and usually you design your rendering around this limitation(draw all the forest vs draw each tree individually) on a fixed system you can design a game that exploits it very eficiently on a variable system you cannot know on a fixed system you can exploit the experimental hardware functions of the GPU on PC you usually never touch anything that is not covered in the version of the api the game is using its not apples to apples comparison
