The world’s first 3TB external hard drive is a product of the notable company Seagate called the FreeAgent GoFlex. What makes this hard drive so special? The usage of USB 3.0 and FireWire 800 should be enough. The built-in NFTS driver for Macs enable you to read and write to Windows NFTS formatted drives. The hard drive comes with a USB 2.0 adapter for $250, and for those extra perks mentioned will cost you some more of course.