I have a trio, and I sometimes bring in my 4th account but normally its just my trio. I can run up to 4 accounts of wow with Octopus maximizer setup with no problems on my machine could probably even run 5 with no issues but I do not have a 5th account and don't really plan on getting a 5th yet, maybe later I will but right now I love the trio, getting a 5th would mean leveling another toon to 60, I could but Im lazy right now and work and life well we have to live don't we?

I sometimes get lag on the accounts but I dont think its because I am running them on same machine probably combo of server + multiaccount set up, like yesterday I was getting some nasty lag in BF needless to say I was not able to finish the instance since the tank was not happy and left the group after a couple of wipes.