What resolution are you gaming at, and do you have a high refresh-rate (such as 144Hz) monitor? At lower resolutions like 1080p and below, the CPU would be limiting frame rates more often than not, whereas at 1440p and above the graphics card would be able to utilize more of its available resources for rendering all those extras pixels.
The 1200 is a somewhat lower-end CPU (especially paired to the 1070 Ti, which is still higher-end), but when overclocked it should hold up relatively well in most games. Some, like the recent AC titles, can be hard on the CPU though, and are known to not run that well on most hardware.