Where are the 128-bit processors?

Question

Programming

Why are 128-bit processors not used?

Answer 1

It is important here what do you mean by 128-bit processors?
1) If the ability to work with 128-bit pointers, then probably this will not be required in the foreseeable future, since 64-bit pointers are enough for now, which can address about 10 ^ 19 bytes.
2) If the ability to work with real numbers with a bit depth of 128-bit, then such a processor was in the 70s IBM_System / 370 , but then the hardware support for such numbers was abandoned as unnecessary.
3) If the ability to work with 128-bit integers, then such a processor was also in the 80s VAX (although 4 32-bit registers were used there to work with 128-bit numbers), but then they also refused hardware support for such numbers .
4) If it’s just the presence of 128-bit registers, then there are such processors for a long time (there are already 256-bit, and 512-bit is expected in the near future), though they store not single numbers, but vectors of real or integer numbers of lesser capacity .

Answer 2

In video cards they cost even more, where it makes sense. In general purpose processors, this is not necessary, at least not yet. Too much complexity of the architecture for a dubious gain.