I've noticed that too, and it's not because my rig is generally sluggish (70-90 FPS even in the middle of a nine ship convoy. Until they discover me, that is), but the moment things start going boom it's a different matter altogether.
I had one battle where I found myself in an unescorted convoy like the one above in the middle of the night (I thought I'd died and gone to Kaleun Heaven, then I realized that I had only two torpedoes left and knew that I hadn't
) and everything was running smoothly even though the weather was acting up and getting worse and there was a lot going on. When I started hitting stuff, though, more specifically when I caused explosions on the enemy ships, the sim would stutter and halt, then come back again.
Now I love my eye candy as much as the next guy, but if every boom sucks up half my rig's available CPU cycles, then it's a bit much.
Whether this is moddable or hidden in the code I don't know and I'd be the last person you'd want to ask in the first place, but it would be nice if something could be done about it.
