SQL Server recommended MAXDOP settings for NUMA
Typically I recommend to my clients leaving the MAXDOP alone.  SQL Server is NUMA aware so it knows which NUMA node the processors are in and which NUMA node the memory is in and it'll do it's best to assign the work to a scheduler on the correct NUMA node for the data that you are looking for.

Looking into this sort of stuff also requires knowing how many NUMA nodes you have.  Is each physical processor in its own NUMA node or are they node in the same NUMA node?