An Introduction to Vectorization

CPU designers are perfectly aware of this, and continue to include vector instructions, because vectorization is still a huge win. The CPU designer is free to try different vector lengths, without the hassle of introducing a new instruction set. For some time after this, the most important computations on typical machines weren’t using 256-bit vector instructions, simply because the necessary software hadn’t been written yet.

Source: blog.cr.yp.to