All the reflection off, shadows and grass distance to minimum, new mesh off, object quality lowest, terrain lowest, antialiasing off.
Nothing had any effect.
In the new clusters the performance for me is always bellow 30.
And even worst when there are zombies around.
Even inside a building, in a empty room, looking at the floor with no zombies around doesn't do better than 30-35.
And the different qualities doesn't make any difference besides ultra (that choke my system).