Overclocking and XMP
Overclocking and XMP
Both upgrades won't make much of a difference.
The i7 warranty promises you can utilize your GPU to its maximum capacity even at stock speeds, with a speed of 4.5Ghz.
Increased RAM might slightly improve performance in certain games like GTA V, but the impact is minimal—2133 or 2400 MB will only noticeably affect a few frames per second.
Your system will still deliver strong performance, so if you're seeing 70, 72, or even 75 FPS, you won't be able to tell without a frame counter.