If there's a port, there has to be sufficient bandwidth available, regardless if anything is connected and what that might be. USB 3.1 Gen 2 supports 10Gbps, so

If there's a port, there has to be sufficient bandwidth available, regardless if anything is connected and what that might be. USB 3.1 Gen 2 supports 10Gbps, so 4 ports means 40Gbps. If it's a MacBook Pro, it has to support Thunderbolt 3 on all ports. That's 160Gbps for 4 ports, or 16 PCIe lanes. That happens to be exactly the number of PCIe lanes the Intel i7-7920HQ CPU has.