My rig:
i7 5960X@4.5
GTX980ti classified tri SLI@ 1515
That rig costed me around $4000 and can play all games at 4k 60fps with smaa at default settings , many games I can even play at 5k 60fps with smaa.
5960x is overkill for gaming though, an i7 6700k would be a much better choice if you are only gonna use that PC for gaming.
Edit:just to make sure you just want a PC that can shit on any game?, or you actually want to spend 7 Gs on a PC?
If that's the case just get 4 Titan x and you would be more than half way there.







