Very old CPUs had support only down to FP16, which is useful in graphics applications.

Then support for Bfloat16 and for INT8 has been added, which are not useful for anything else but AI/ML applications. Then support for FP8 has been added. Even smaller formats are supported only on some very recent GPUs.

If you have a recent enough GPU, it might support something like float2 or float4, but if you have an older GPU you must convert the short format to the next bigger format that is supported, before performing some operations.