it's the game. people with GTX 980s are struggling to play it too. Ubisoft released a very broken game.
You can try disconnecting from the net, i know a many people on PC, PS4 and xb1 found playing offline really helped the fps. But yeah, the draw calls issue is probably at the heart of the problem (btw: it plays like junk on the consoles as well, not sure how ubisoft thought this was an acceptable release, but there it is)