Annoying Mouse Jitter in Rainbow Six: Siege - HELP!

[DrumsXO]

So, I have this annoying mouse jitter issue plaguing me in Rainbow Six: Siege. When looking around with my character, I get this jittery, tick-tick-tick-tick feel instead of a smooth feel. This only happens when looking around, and only when using my mouse. You'll see me switch to a controller in the second half of the video and the footage will become flawlessly smooth; no jitter.

I've tried adjusting my DPI, my Poll Rate, playing around with VSync and even using RadeonPro to adjust the Flip Queue Size, all to no avail. I don't know what else to try!

CPU: i5-4670K
GPU: HD 7970 3GB
RAM: 8GB
Mouse: Logitech G500

 

[PC-4LIFE]

Mouse stutter can be caused by insufficient memory.
Consider upgrading to 16GB, you should see an improvement.