External GPU Docking Station?

Jeff u cannot connect eGPU to SP4's miniDP because it is display OUT not IN. The only way is thru USB, and i dunno if any of this will funtion. AFAIK, USB 3.0 will bottleneck any eGPU connection, so u cannot take full advantage of it. We need either Thunderbolt or USB-C, and we don't have any of it :(