Same issue since they added japanesse carriers and american battleships, before that patch in alpha, beta phase of the game i run smoothly at locked 60 FPS at high settings, now it is almost unplayable when it dropping between 5-60 FPS. I tried to run game at max settings (max 50FPS) and low settings with everything off and same issue. My specs are FX 8320, R9 280 8GB ram win7 64bit and yes all my drivers are up to date because Iam AMD user. Thats why checking for updates constantly myself. I stop playing game since that patch back then and now i came back with hope it will be fixed when it is in OBT (few patches later) and nothing change.