Thunderbolt

There are three Thunderbolt versions: 1(TB), 2(TB2) and 3 (TB3)

If you don’t use Thunderbolt, you can lower cost by custom build of a Hackintosh without Thunderbolt. Thunderbolt can still be added later using a Thunderbolt PCIe card.

USB3.0 (and increasingly USB3.1) is included free and provides high speed data transfer.