The original release was for Amiga and Mac. The C64 version followed around the same time as the PC version, though apparently the C64 version was the original.
replyI was running Sim City 2000 inside Win 3.1 on an 386 with 33MHz (I had 16MB of ram though). But it was virtually unplayable.
replySim City 2000 is a very different (and computationally more demanding) game than the original Sim City.
replyIn my youth, people would quit Windows 3.1 to run games in DOS, because the overhead of the OS was too much.
replyDon’t know if that could be an explanation.