I am working on a custom resolve tile shader for a client. I see a big difference in performance depending on where we write to:
1- the resolve texture of the color attachment
2- a rw tile shader texture set via [renderEncoder setTileTexture: myResolvedTexture]
Option 2 is more than twice as slow than option 1.
Our compute shader writes to 4 UAVs so just using the resolve texture entry is not possible.
Why such a difference as there is no more data being written? Can option 2 be as fast as option 1?
I can demonstrate the issue in a modified version of the Multisample code sample.