a_delo: Even with the last patch turn processing get slower the longer the game drags on.
The hardware is good enough to run smoothly Diablo IV, so I presume Old World should not be a problem
Old World is heavily CPU dependent for AI turn speed and benefits a lot from additional CPU cores.
With a lot of units on the map in the late game, a huge amount of calculations are happening in order for the AI to perform well.
Playing on smaller maps with less opponents will help late game speed.
There is a setting in the UI options for Slow AI, which intentionally slows the AI down in order to preserve CPU resource for background tasks - if you want turns to process as fast as possible then make sure that is turned off.
