intel did this back in the days when they sold 80486 CPU with DX and SX designation, the latter lacking math coprocessor a.k.a FPU. In assembly line, all chips

intel did this back in the days when they sold 80486 CPU with DX and SX designation, the latter lacking math coprocessor a.k.a FPU. In assembly line, all chips would start off as DX with math FPU. In order to make SX variant, they would use just disable FPU function, though they eventually made different chip to cut out FPU altogether.