We know that AMD, like most silicon design shops, bins its products.
So here comes the problem:
When you approach AMD with a big semi custom design proposal, e.g. the PS4 pro SoC, you are essentially asking AMD to make a huge die that nobody but you want.
Because the silicon size is huge (~350mm2), there is bound to be a lot of defective chips.
Then, what happens to those chips?
We know you would not accept them because you make your design just powerful enough to function, and any defect will cause the chip to fail to meet performance objectives.
We also know that AMD cannot bin them to a lower designation number because nobody but you want the design.
We can deduce that that essentially dictates that the yield is very low.
How does AMD deal with this issue? Does it just accept very low profit margins then?
They use a laser and do a bit of surgery, then sell them as desktop chips without the proprietary software and high specs of the console variants. Also, because they are larger chips, there is room for redundancies to mitigate duff chips. The PS4's chip has 10% OP and XBOX One has 11% OP in stream processor count, for example.