I have a gtx 1070 itx msi, 8gb of ram and an i7 2600, I was wondering if I should upgrade it to an i5 9600k with 16gb ram or something like that because in games like GTA 5, assassins creed origins I can't run them in ultra or very high settings at 1080p 60fps or when I turn vsync off there is a lot of tearing. in games like rainbow six siege in ultra, I can't get the T AA x2 without going under 60 fps, I feel like a CPU upgrade would give me better performance, when I benchmark assassins creed odyssey the fps are really unstable: FPS min: 10 FPS: avg 43 FPS max: 73 with the graphics in ultra, when I lower them they are still really bad and unstable, Idk if an i5 9600k would be too much because I have a 60 Hz monitor, but the i7 2600 doesn't let me play games at ultra 1080p 60fps smoothly.
(note: I have a 1070 itx cuz a bigger one couldn't fit in my case xD)