What are the possible effects of having too many windows/tabs open other than the "freezing" problem?

I know the worst that could happen is it freezes and you have to reboot. Let’s say the 10th wondow/tab makes it freeze, but what little things could happen as side effects of having too many tabs, before you open the 10th tab? Loading takes longer and longer the more tabs you have open? I don’t know… but what else?