Complex sentence: In 2007, "Shrek the Third" required over 20 million CPU render hours, and the 2010 3D release of "Shrek Forever After" demanded more than 50 million CPU render hours on behalf of rendering double amount of frames.
Split into simpler sentences: In 2007, "Shrek the Third" required over 20 million CPU render hours. And the 2010 3D release of "Shrek Forever After" demanded more than 50 million CPU render hours on behalf of rendering double amount of frames.