Nope. Even if your physics engine could deal with the rotation of the first gear in one "unit", and batch the rotation of that gear a million times in a "super

Nope. Even if your physics engine could deal with the rotation of the first gear in one "unit", and batch the rotation of that gear a million times in a "super unit", then calculate a million "super units" each second, it would still take longer than the universe has been around, by 10^70 times, to complete one rotation of the final gear.