1080 ti is far too much for 1080p, at that resolution even a 7700k at 5 GHz will bottleneck it in 99% of games. At 1440p, the 1500X will bottleneck it in many more cases than the 7700k will and it's really not worth it to have a 1080 ti unless you're at 144hz. A 1500X and 1080 ti would be a great fit for 4k60. If you haven't bought the GPU yet, I would consider downgrading to a GTX 1080 or 1070, there's not much use spending $700 on a GPU when you won't be able to tell the difference from a $400 GPU at the resolution you're playing at.