Perfoarmance degradation and lag in Update 4

Since update 4 released I can no longer play the game at the highest speed setting, the lag makes the game uplayable. The delay on key and mouse input is well over a second. It still runs fine on speed 2. Before Update #4 I would always play on Ultra until I have roughly 200 beavers than I would lower the graphics quality to get the game to run at speed 3. But now I cannot run the game at speed 3 even when graphics are set to low.