Recent FPS drops/performance issues - GTX 780 Ti

[DeferentUrchin]

As of about a week ago, I started recently having significant drops in frame rate in both city areas and relatively non-taxing zones and areas of the game that have NEVER had performance issues. I have the game v-synced to a buttery 60 fps at almost all times, and have recently been having the frame rate in the aforementioned areas drop down to 40-45fps and sit there. There hasn't been a single software/hardware change or update on my system to correlate with this issue. I've also made no alterations to the in-game graphics settings, they were and have always been at complete maximum for every setting.

Has something about the game changed/been updated to possibly be causing this problem?