I'm not sure where you got the info about SATA 4 connectors being available to the masses but yes there are USB to SATA adapters which are primarily used to hook up a laptop drive to your USB port and backup data, either which way. They are not meant to be connected to your motherboard's SATA DATA ports, if you can find one that is, since they don't exist(connectors from USB to SATA on the motherboard).