At release, the game required a permanent internet connection to be played. While this decision was unpopular in itself, the controversy really started because EA's servers were completely overburdened after release and many players could not start their singleplayer game because they could not log in or the servers lost their savegames. According to Maxis, this was necessary because many calculations for the advanced simulation had to be outsourced to the servers. However, two revelations after release placed doubt to this statement:
- The people of SimCity are not individually simulated and just choose a random place to work/live on the go. There is also no traffic simulation besides "shortest way to the goal".
- Shortly after release there was an unofficial offline patch and the game functioned just as well for 20 minutes until an internal timer kicked in.
An official offline patch followed one year after release.