These GPU architectures are too complicated for my taste. It reminds me of the days of segmented memory, and makes me feel like having to jump through hoops all the time. I'm curious if people have tried to invent something more elegant, and where these approaches have failed. Also, the fact that NVidia has probably patented this particular architecture makes it less interesting for me to really dig into.
It's a good question actually. Intel tried to make a GPU called Larrabee that was mostly a bunch of small x86 cores with giant vector units. Turns out that it couldn't compete in rendering performance on existing games (in 2010) without the fixed function units that GPUs have, so they canceled it as a GPU. It did result in the AVX-512 instruction set though. I think the idea still has promise but there's a chicken an…
Nanite uses compute shader rasterization partly because of the quad overdraw problem since they are targeting near 1 triangle per pixel. But they also say they are using traditional rasterization with recent hardware's addition of mesh shaders when it is faster (which remove a different set of fixed function stuff though, for transform, so still makes the same point).