I just rejected a map that generated slightly more than 88 energy/second. All from a single pile of stacked reactors. Just for the heck of it, I calculated how many reactors that would be - about 290 reactors.
Guess how much that map lagged. The author added a remark "not good with slow computers."
Why? I could not push the space bar 289 times. The author must have a really good computer or must think that most people do.