In sims 3 I did 26 generations now in sims 4 I am trying again, but I have not gotten very far as I have been jumping around with different challenges, but I am still working on them.
It took me quite awhile because I did not age anyone up. I just played each generation from birth to death without ageing anyone.
It is more fun that way.
Oh by the way in sims 4 I lost my generation saves, it was my fault as I saved another save over them, So I am starting over, now, I was a little upset, The only save was my first generation and she was not even pregnant as yet. I feel bad as I lost the kids and all.