Guides I've Contributed To
I believe it is due to the difficulty removing/replacing the RAM and the difficulty of reassembly due to the cable routing. These are the orange and red dots on the overview.
CUDA Cores are a type of stream processors. nVidia started calling them CUDA Cores around the Fermi architecture. The differences are marketing and a difference in instruction set between AMD and nVidia stream processors, but they both fit into that categorization.