Mine hits around 1,162,248kb in game, which is quite a lot but with at least 2gb ram and plenty of virtual ram it should run fine.
I think this is more of a GAE bug or something, maybe your graphics drivers or something though if other games work fine then maybe not, if other GAE mods don't work either then it's GAE or there's something up with your setup.
I usually run two instances of my mod when testing too and they run fine, maybe when there're a few hundred units out it begins to lag a little but for having it running twice with little lag like that is ok.