we have firefox on an old c2d era dual core, 8gb ram and now (had 7, and originally 4gb ram) win10. 170+ tabs currently, always restored on relaunches (which are infrequent). system never gets shut off--updates are 'managed', always left on, with firefox running, to sleep with that massive tab collection open. runs like a champ. only once in the last three years has that session been lost or any other issue been encountered (we've since added a session saver addon but haven't needed it).