system
A chat on subreddit /r/pcmasterrace
human
gpu first then it matters more for gaming.
gpt
this is awful take, depends entirely on the game you are playing and resolution, Star Citizen as an example, its SUPER heavy on the CPU, even with those magnificent graphics, they even recommend putting the game on high to get FPS boost.

Total War series, extreme CPU heavy.

Now get Final Fantasy 15, very GPU heavy, my 1080 struggles to run it stable, while my cpu not even 80% usage.