It explains why AMD cards are generally worse for games in the past and why DX 12 will be such a boon on AMD cards. I might actually go AMD next time.
If you didnt want to watch the video, the main difference between the two is that the AMD cards have a hardware scheduler and NVidia has a software scheduler. If a game using DX11 is not directly developers for the AMD card, it will suffer greatly. on the converse NVidia cards are much harsher on the CPU because scheduling is done on the CPU. From what i can tell CPU usage goes up almost 50% on NVidia cards.
AMD cards get massive gains in DX12 because DX12 is designed with AMD's hardware scheduler in mind so games by default use it. NVidia cards still go through a lot of CPU usage AFAIK.