I remember reading at the time that they couldn't reasonably get the connector throughput working. The original 5K iMacs used custom high bandwidth internal int

I remember reading at the time that they couldn't reasonably get the connector throughput working. The original 5K iMacs used custom high bandwidth internal interconnects because there weren't any standard spec interconnects that could do the job, therefore no commercial external cables or connectors up to it either. It might be possible in theory now, but I suppose that ship has sailed.