I am currently in 2032 with a medium map and have quite a few big towns, with my “capital” about 1250 population. Upto about year 2000 performance was very good even with all settings maxed however it’s since become very choppy to the point it’s almost unplayable and I think I will have to abandon the game and start a new one. I have a new computer which I bought specifically for playing TF as my old one was not up-to the job (it was 5 years old). The machine cost about 1000 euro so it’s not a cheap one and I have a quad core i7 CPU and Nvidia GeForce 860M GFX.
I tried reducing the graphics settings, turning off HDR, reflections/shadows etc which did not seem to do much to help making me think my GFX is not the problem. According to windows task manager CPU usage is under 20% and I still have 4GB of RAM free so I have no idea what is causing the slowness.
Many thanks for sorting this. I will look forward to being able to play with big cities.