Why is SATA Multilane better than SATA Port Multiplier? Simple - it's faster, much faster. A Port Multiplier shares a single 3Gb/s connection to your host, whereas a Multilane (sometimes referred to as "Infiniband") interface has each hard drive on it's own 3Gb/s channel.

Use a Multilane interface in your host and it's partner interface in your external storage box - link the 2 with the Multilane/Infinband interface cable and you have the fastest available way to move data between your drives and your computer currently available.