[Note: The crosstie will include the fix which is described bellow]
The recent changes to CrossOver 13 bring performance improvements for a lot of games. Terraria seems to be one title where CSMT causes a slight performance issue that is easy to spot when moving between biomes which causes the background image to change. At that moment there is a stutter.
Create a file called terraria.reg and copy the follwoing into it:
REGEDIT4
[HKEY_CURRENT_USER\Software\Wine\AppDefaults\Terraria.exe\Direct3D]
"CSMT"="disabled"
Open the CrossOver bottle manager, select the bottle in which Terraria is installed and the click on the Run Command button. In the box that appears type regedit. In the window that just opened go to Registry -> Import registry file. Find the terraria.reg file that you've just created, select it and click on the Open button.
That's it! You should now have no more performance issues with the game.