I have come across some info regarding VR quality that isn't obvious to find and set.
These settings made a substantial increase in quality for me.
First thing is if you are also running a monitor as a mirror ... unplug it, I found this greatly increase smoothness in VR as the graphics card was running a 32 inch screen that I wasn't using, while in VR anyway.
Second is for those guys using the Oculus Rift S .. there is a hidden setting down in the depths of the software that unless you are told, you wouldn't necessarily find it. Again this made a big change for me in terms of pixel quality. Refer to the attached pics
Go to Device Settings, click the arrow at far right, scroll down to Graphics Preference and select Prioritise Quality.
NikonGuy <S>