An Engineer Guided Tour of Surface Pro 4
If you are wondering about the difference between Surface Pro 3 versus Surface Pro 4, the difference is in what's inside. The lead engineer behind Surface Pro 4, Dave Mitchell, shares the details behind performance design enhancements and available processor configurations for this major new edition to the Surface family. He also reviews the best-in class screen; Windows 10 optimizations, and improvements made to the type cover and pen.
Source: Microsoft Mechanics