This is very educational and I highly recommend it especially if you spend a lot of money on these parts. It gives you a different perspective on what went into building these GPUs, especially the stock PCBs.
R9 290X PCB breakdown + power and voltage mods.
GTX 780 Ti Classified PCB Breakdown
GTX 1080 FE PCB breakdown and power limit mod
Custom GTX 1080 PCB run down