Discrete cards do not always automatically disable IGPs on the motherboard or CPU. In fact, you often need to disable them yourself if you want to. Also, an integrated GPU is not always an integrated graphics card, nor is it always an on-board GPU. If it is on the CPU like almost all modern IGPs, then it is on-die, not on-board. It is also not an integrated graphics card, it is an integrated graphics processor. There is a difference. If you want to wave around terminology, then please do it correctly.