Heh, somebody post a screenie of a city with 100 population. I'd like to see that.
Well, it was not me, sorry; but i wouldn't be surprised at all if even much higher than 100 would actually be very possible. Let's try to figure out - very simply and rudely, - a sort of theoretical limit to the city's population:
max "workable" city size = 37 tiles;
max regular food per tile = 4 (grasslands; some more can be from resources, which i omit - those can compensate somewhat for some tiles being plains, for example);
therefore, let's say that
base food from tiles ~= 148 food
additional base food:
+2 from Granary
+2 from Water Mill (being next to a river, that is)
+5 from Hospital
+6 from Hanging Gardens
+12 from Maritime allied city-states (assuming ~4 as realistic number of Maritime city-states on a huge map, and assuming we are talking the Capitol city, which gets +3 per each Maritime ally)
+60 from 10 domestic caravans, each bringing in +6 food
therefore,
base food total ~= 235 food
multipliers to total food:
+15% from Floating Gardens (playing Aztecs for max population cities is sort of expected, right?);
+10% from Temple of Artemis;
therefore,
total food supply ~= 294
Which is sufficient to have 155 population, assuming Freedom ideology's tenet which reduces specialist's food consumption by 50% (to 1) is taken, and it's a city which has 17 specialists total - which is the case in a city with a Windmill, Writers' Guild, Artists' Guild, Musicians' Guild and all the usual specialists' buildings present.
1 extra population is then possible via CN tower.
Therefore, a "somewhat theoretical" limit to a city's population in game - is 156. I am not sure how long time it'd take to get to anything past 150, though, because _time_ costs of each new citizen skyrocket to near infinity when getting last few dozens of population. With dwindling growth as city gets bigger and bigger, it would take a LOOONG time. But, should be doable, i guess... %)
On the other hand, growth to 100, given all the above food sources, - should take quite short time indeed. With a surplus of 200+ food, further much boosted by bonuses to growth (which are "we love the King!" day for +25% surplus, some religious beliefs giving +10%), and of course Aqueduct + Medical Lab present, growth from ~40 to to 100 population would possibly take ~200 turns or even less. I guess.
So i'd say, 100+ population city - provided extremely "grasslandish" location with quite a bunch +food resources like wheat and cattle, - is totally doable in-game, should one aim to do it specifically (playing Aztecs, having one's capitol in such a location for Maritime boosts, etc). If the player keeps going to and through the time limit, 140+ should be eventually possible...
On a map created for max population cities by hand, though, it gets even much higher. Plains + bananas = 6 food per tile end-game, 37 such tiles should make possible 200+ population city... %)
P.S. Ugh, i forgot that policy from Tradition tree which gives +2 base food to the capital. Well, that CN tower thing is not likely to be constructed _after_ the city gets to max size, though - the player would need to keep AI's from getting it for many hundreds turns, i guess. Which is doable but very boring, i guess. So i'll keep that limit at 156 anyhows. Give or take a few. ><
