PySide TableView chokes at around 80 million lines

[Petter]

I have attached two (very) small files which describe an application with a QTableView with a custom Model. 

The rowCount() method of the model returns 70 * 10**6 and the application runs fine, starts instantly and uses a small amount of memory (Windows 7, 64-bit, Python 2.7 64-bit). However, when I change the number of rows to 90 * 10**6 the application is completely unable to start. Why?