Since Stars opened up 24 tabling I decided to see what my limit was for short handed. I got to 16 and then couldn't even open the lobby between actions:
I have a dual monitor set up though (22" + 19"), but for some reason the PokerStars software decided to put 6 tables on my 22" and 10 on my 19".
Here are the stats:
This was about an hour and a half.