I had a 680i that I went from a gtx 660 to a 290x and games went up 15-20 fps. When I went from the 680i to z97 and the 290x, frames doubled and even tripled in some games. cpu is going to be your bottleneck, and you might want to see if your board can do a 771 mod and buy a x5492 xeon off ebay and clock it up high. if your going to kaby lake soon, 780i and 550ti to a 1070 will be a major upgrade. I got my 1070 now and it takes everything I throw at it.