Frame Rate Drop

[Overkill]

I was attacking Truk Atoll earlier today. When I closed to within 20 miles of the main anchorage my frame rate outside dropped from the high 30's to below 10fps. At the map the frame rate was also low...around 50fps rather than 100+ like normal. I made my attack and then headed away at top speed. I thought it was just the number of ships and the proximity to land that was causing the issue but now I'm over 200 miles from Truk, on my way back to Pearl, and the fps is still staying low. If my time acceleration is tuned up the frame rate drops below 5fps at the map screen.


I'm thinking the memory is getting bogged and not being freed up even when I leave the congested area. If I leave the mission the fps does go back up but, when I load the mission back up, from a save point after the Truk attack, it starts off very low again.

Anyone else have this issue before and know a fix? The only mod I'm using is TMO with the patch.