It's true that simulation speed is independent of graphics speed in Supreme Commander. The game lets you adjust the simulation speed, although of course if there are too many things happening your CPU can't keep up and it slows back down. If you have a fast computer or there are not many things happening you can run the simulation at 100 ticks per second if you want (although it will be hard to play because everything goes too fast).

That figure comes from the presentation linked to by this post, but I'm not sure where it came from before that. In any case the team had performance problems for a comparatively trivial amount of processing work. Looking at the game you could easily run that game logic at 10000 updates per second when you implement it in C/C++.