As other answers already show, the limit in the sheets themselves has not changed, it is still 1M lines.
The amount of data that you can process in Powerpivot has changed. This data can be read into the Powerpivot cache and modified / extended using DAX formulas and combined with pivot tables. However, you cannot “edit” them as you can with regular Excel data.
Before you were limited by a 2 GB / 4 GB barrier, which already allowed several million rows, depending on your data set. With Excel 2013, this limit is now gone - the only limit is the memory of your computers. However, you still cannot edit raw data, only process it (DAX) and pivot (pivot tables)!
Peter Albert
source share