I've found that turning on 2x MSAA has a huge performance impact, way more than I would expect.
To investigate I created a new Unity project (see below for versions), created an empty scene and set the cameras in the WaveVR prefab to solid color clear mode. I then connected the Snapdragon profiler and found something that seems very strange. The fragments shaded per second value goes up a lot when MSAA is turned on:
MSAA disabled: Approx 340 million fragments / second.
MSAA 2x : Approx 1700 million fragments / second.
MSAA 4x : Approx 2400 million fragments / second
The first value makes sense and covers the distortion pass (2880*1600 * 75 = 345.6M). But just turning on 2x MSAA increases the number of fragments shaded by 5x. And with 4x MSAA it's rendering 7x the number of fragments.
Can this be right? I can't see why the number of fragments would increase at all. Nevermind this much.
I'm porting a game from the Oculus Go, where we use 4x MSAA without any problems and I know that switching between 2x and 4x made very little difference for us. So it's strange to see such a huge impact here.
Versions: Unity : 5.6.3f1 Wave SDK : Reproducted on 2.1.8 and 3.0.2 Focus system : 1.69.623.3