I think one of the first 'mass market' processors that used this technique was the Intel 486SX, back in the early 1990s. It was simply a 486DX which had the fus

I think one of the first 'mass market' processors that used this technique was the Intel 486SX, back in the early 1990s. It was simply a 486DX which had the fuses connecting the FPU blown. I believe binning by clock-speed has been used for a lot longer; the 486 33MHz parts being the same as 66MHz but having failed some sort of QA, which meant that overclocking could be attempted at fairly low risk, as long as attention was paid to cooling and you didn't mind the risk of the CPU failing completely earlier than expected.