CPU Binning is a form of recycling. You see, when you make a CPU, you don’t make them one at a time. They are produced on circular sheets of silicon called ‘wafers’. The problem is, the photo-lithographic process used to make these product’s isn’t perfect. And even if it was, the rooms that they are made in aren’t perfect, although manufactures certainly try their best to make them so.
But one little spec of dust on a fragile CPU die, and that’s that. It’s over. Useless. Trash. Garbage. Well, it would be. If not for the practice of CPU binning. Instead of trashing these chips, which would drastically increase costs, they instead recycle them. No, they don’t grind them up into silicon dust and reform them into new chips. That would be more like aluminum, steel, or plastic recycling.
There is no way that would work for chip manufacturing. Instead, they build in sophisticated testing circuitry into the CPUs. After a wafer is manufactured, each CPU is tested.
If the CPU in question cannot run at maximum performance due to a tiny manufacturing error, then the microcode on the CPU is reprogrammed to either reduce the chips clock speed to a stable figure, or in worse cases, entire sections of the chip are disable. This is how you end up with the lower end chips like Ryzen 7, 5, and 3.
