It's been choppy since the beginning, truthfully it's better since they killed the exploration treaty and reduced it to only one faction, however as the game expands on the larger maps with more items the ship movement gets choppy.  Don't know exactly what points to this could be the GPU.  I know my GPU is has 2gb memory looked up yours and couldn't find how much memory yours has built in.  (Although once again turning down the video settings doesn't seem to have any impact on this.)

Tickets have been created in the past and, I believe they are aware this still is an issue and, in fact maybe the map size reduction in 1.9 was an attempt to minimize or reduce this further (although they increase the number of objects in all map sizes).  Either way I hope they continue to optimize the game and help resolve this issue going forward.

I noticed today that at end of turn the game moves every ship "simultaneously", by visiting each ship in a loop and move it by one hex, until all ships have used up their movement points. May it be that the game does this also for ships not on screen and that causes the substantial delay (the more, the further the game has progressed since there are more ships to move ...)?

Thanks for the reports folks.  We haven't see this internally, but we'll look into it and see what we can find out.  

Before I forget a clarification: I also have ships moving choppily when I move them manually, not only at end of turn.