AMD vs NV Drivers: A Brief History and Understanding Scheduling & CPU Overhead

This topic is something I really wanted to cover last year, but due to work scheduling (hah!), I was never able to fully formulate it into a presentation format. But I felt it had to be covered before Vega's release. Hopefully the presentation makes sense for you guys, it's not an easy topic to talk about in simple terms. To better clarify, I have simplified the presentation to talk about the rendering thread handling draw calls, but games are a lot more than that, often shaders takes considerable CPU cycles, and for DX11, both AMD & NV engage in shader re-optimization whereby they override the game developers code with their optimal variant. These steps all eat CPU cycles. So the more that it has to be done (because the game was poorly optimized), the more “CPU overhead“ there is, on top of everything else. This topic is really complex because we're dealing with how games are made and how it interacts with both vendor hardware & drivers. I apologize if during the simplification process, some accuracy or