How did the author figure all of that information out?
From part 3:

>Links

>The tech that built an empire: how Rockstar created the world of GTA 5 featuring an interview of Aaron Garbut. http://www.techradar.com/news/gaming/the-tech-that-built-an-...

>GTA V NVIDIA Performance Guide with details about the different graphics settings. http://www.geforce.com/whats-new/guides/grand-theft-auto-v-p...

>Renderdoc which made picking into GTA V internals a breeze. https://github.com/baldurk/renderdoc