There are many areas where performance is lower than might be expected, but the only unresolvable problem I've encountered--on hardware that should otherwise handle things without issue--is the stutter that occurs in ground CZs any time a dropship spawns in.
This is a frame time and GPU utilization plot I took this morning (on 4.0.0.1700) in a large settlement CZ (open it in a new tab and 100% it...it's 16k pixels wide to show more detail):
On this 5800X3D + RTX 4090 setup, I'm pretty much completely CPU/memory limited, even at 2400p with way past ultra graphics settings, but that's not the main problem. See all those spikes past 30ms? Those are noticeable and correlate almost entirely with new dropships spawning into the instance. A faster CPU reduces the magnitude of the spikes (as well as increase average fps), but cannot eliminate them.
At the end of the graph you can see where the opposing side ran out of reinforcements and the dropships stopped spawning. The AI is still active and the game is still CPU limited (GPU utilization still well off maximum, with no frame rate cap) but frame times are much tighter, with no spikes of note.
This is a frame time and GPU utilization plot I took this morning (on 4.0.0.1700) in a large settlement CZ (open it in a new tab and 100% it...it's 16k pixels wide to show more detail):

On this 5800X3D + RTX 4090 setup, I'm pretty much completely CPU/memory limited, even at 2400p with way past ultra graphics settings, but that's not the main problem. See all those spikes past 30ms? Those are noticeable and correlate almost entirely with new dropships spawning into the instance. A faster CPU reduces the magnitude of the spikes (as well as increase average fps), but cannot eliminate them.
At the end of the graph you can see where the opposing side ran out of reinforcements and the dropships stopped spawning. The AI is still active and the game is still CPU limited (GPU utilization still well off maximum, with no frame rate cap) but frame times are much tighter, with no spikes of note.