I have a 2015 Mac - i7, 16 gigs of ram, a 4GB graphic card. One of the best things about a Mac for music is that even the stock Mac drivers for sound are miles better than windows. For example, I am able to run a multi-track project with superior drummer and halion without even turning on my external sound card - it's that powerful.
As far as graphics, I used to game quite a fair bit. I have a windows partition on my mac for games and I was able to play graphic intensive games like GTA5 at 4k resolution :o