The Thermaltake BlacX 5G is an upgrade in the BlacX line of HDD docking stations. The BlacX 5G boasts more speed and up to date support. The 5G tag is for the USB 3.0 and SATA III internal makeover. SATA III has a 6Gb/s theoretical speed, while USB 3.0 has 5Gb/s. So, with this BlacX upgrade, you should be able to get the most out of your external HDD dock.