Assassin's Creed Unity Optimization Plans
 

I have an idea, how about rebuilding the game from scratch? We can tell you that we have detected a distinct discrepancy between what we observed in the pre-launch versus post-launch environment. In spite of our testing, it looks like the instruction queue is becoming overloaded and impacting performance. We have several fixes we are exploring right now and will continue to update you with our progress of what is working and how quickly we can implement these fixes in the game in the weeks ahead.

http://www.hardocp.com/news/2014/11/...ization_plans/