Hello,
I have crusade expansion installed, and when I play the campaign, with default ships, all my combats goes to 10 FPS average, and with enough time, the FPS goes even worst.
My PC should handle that kind of graphics (its better than recommended spec), but I can't even play at 20 FPS on combat (and on certain tactical zoom levels). I'm not asking for 60FPS, but at least 20-25, just enough to cheat my eyes.
You should change recommended specs.. the current ones are VERY misleading.
I have latest drivers for ALL my devices, and latest windows 10 patches.
STEPS TO REPRODUCE:
1) Play the game and SEE all the combats animations from beginning to end, and sometimes use x4 speed.
2) after 45-60 mins of gameplay, you can appreciate a FPS dropdown from 60 to 30 in tactical view, and from 45 to 5-15 FPS in combat mode no mater the ships quantity involved
UPDATE: I just test using GPU-Z and my GPU is at 60-70% during a battle, but the FPS are VERY low. CPU is also almost idle. I just notice that if I play for about 2 hs.. the average FPS goes from 30 (at fresh start the game) down to 5-10 at combats. It's definitely some kind of memory leak and optimisation problem.
Tested with 3 small ships vs 1 frigate. 15 FPS 
SD support tool logs: https://www.dropbox.com/s/y3c9e5r7v28rctc/franc-FRANCO-PC-05.06.17-logs.zip?dl=0
* My general PC specs: Windows 10 pro 64 bits. AMD FX-8350 8cores@4Ghz, motherboard Gigabyte GA-970A-DS3P, 16Gb ram, AMD Radeon R9 280x, SSD 840 EVO 500Gb.
* My PC dxdiag: http://pastebin.com/CfvFtRDw
