With 1080Ti at 1440p you are more likely GPU bound on many new games.
If you play single thread games like WOT yes you will see some different from moving to DDR4 platform of Broadwel-E or better level of IPC/perf.
From my experience, I moved from 4930K @ 4.5Ghz to 6700K @ 4.9Ghz and saw improvements in WOT, Stellaris, CK2.
However that didn't change regardless of the subsequent CPUs used. 6800K @ 4Ghz, 1700X & 1800X @ 4Ghz or 8600K @ 5.2Ghz. Performance remained the same. Though the system was better over the quad core, and more things could run on the background while gaming, like internet radio streaming, TS, and couple of browser windows.