Example: I cleared my game stuttering when I went into the Nvidia Control Panel / Manage 3D Settings / Program Settings / XCOM2 and changed a few things.
Anisotropic Filtering OFF
Antialiasing - FXAA ON
Antialiasing Gamma Correction / Mode / Setting and Transarency OFF
Texture Filtering Negative LOD Bias (a biggy) CLAMP as this conflicts with the FXAA
Texture Filtering Quality - High Performance
The rest is ON

Hope this helps a few coz my game stuttered and paused like crazy. If your one of the unfortunates who has an ATI..no idea