@Koji well i can't say the specific numbers of alts you can log(im guessing 21 accounts) but i do know for sure that IGG limits the number of alts you can log into 1 IP Address because of botters and stuff.

@Dark well i happen to have a second laptop but its pretty old and can only run 3 at most with no lag. But i only need about 6 alts to be open, which my new laptop can pretty much handle.

4 chars for training, 1 for compounding/selling and the last one is for collecting and building.
I only use my old laptop when theres like a drop event.

Ive seen many other people that can run more than me like around 15+. They have a badass PC.