I have the 4790K as well it will be fine to use that till you get a proper GPU. I actually played Tomb raider 2013 on my system Prior to me getting my GTX 780 TI matrix platinum. I was shocked to see that the onboard GPU could even launch it . It looked crappy but it still played and got me through a few days lol!
Corsair Grapgite 760 T , Maximus VII Hero, I7 4790K ( Trying to find stable OC ) , 8GB Corsair Vengance Ram DDR3 1866, Asus GTX 780 TI Matrix Platinum GPU, OCZ fatality 750 Watt PSU, Custom water cooling Loop