It was very laggy in the early versions. But bearing in mind that viruses can only multiply if new neutral spawns enter the game, i simply put a limit on that makes sure when the virus count raches 400 in total, the trigger controlling the spawns is turned off.
The heroes used to get replaced but it was interfering with the revival so i took it out.
There are lag issues when a lot if viruses die in one go. Infact i was wondering if anybody had a list of all the unit models and their polygon counts sp i can pick the ones that will put the lowest amount of strain on the system.
That being said the lag is always graphical, and never results in players having to be dropped.