I just installed with an MSI GTX 970 graphics card on a motherboard MSI Z97 Gaming 5, and I can run all the games in 1080p Ultra; It would seem that the 4k be done without too much trouble but with no suitable screen, I can not attest
You decide if you want to spend 100 more for an i7 4790k, but I do not think the difference is justified if you rely primarily make gaming!