As of 2009, SATA 6Gb/s is the newest generation architecture for platter-based hard drives. The "6Gb/s" refers to the data transfer rate of 6 gigabits per second, twice the speed of the previous generation SATA. The Serial ATA International Organization (SATA-IO) that designs SATA standards has requested that this third-generation SATA be referred to as SATA 6Gb/s to avoid adding potential confusion to SATA nomenclature already bumbled by confusing second-generation names.
SATA technology changed the landscape of hard drive technology by switching from wide, inconvenient parallel ATA (PATA) data cables and connectors, to narrow serial cables and connectors. The switch to full duplex serial communication opened the door to faster speeds than parallel technology could handle, and also opened up the interior of computer cases allowing for greater air flow, vital to faster computer processor units (CPUs) and higher capacity disk drives.
Original SATA, also known as SATA 150 or SATA/150, had a maximum data transfer rate of 1.5 Gb/s or 150 Megabytes per second (MB/s). The fastest PATA drives could compete with original SATA, but PATA was maxing out its clunkier architecture while SATA was just getting started.
Second-generation SATA, often referred to as SATA II, doubled the speed to 3 Gb/s, or 300 MB/s. Due to the data transfer rate, SATA II was also called SATA 300, SATA/300 or SATA 3. You can already see the confusion with “SATA II” being synonymous with “SATA 3.”
Now add third-generation SATA and it’s clear why the SATA-IO does not want the newest iteration to be referred to as SATA 3, SATA III or even Third Generation SATA. Calling it by its data transfer rate, “SATA 6Gb/s” makes the specification immediately clear.
SATA 6Gb/s drives are expected to hit the market in the second quarter of 2009. According to SATA-IO, the technology is backward compatible with previous versions of SATA, using the same cables and connectors. Since SATA drives make up nearly 100% of drives in use today, upgrading to SATA 6Gb/s as easy as buying and installing a new drive.
SATA 6Gb/s is coming just in time to pair up nicely with USB 3.0, a newer USB standard. USB 3.0 supports a maximum theoretical speed of 600 MB/s, matching perfectly with the newest generation SATA. While USB 3.0 might not realize its maximum throughout in the real world, you can’t help but imagine all the time you’ll save with an external drive enclosure that supports USB 3.0, and two or more SATA 6Gb/s drives to speed through those disk-clone backups.
While some new technologies introduce as many new problems as they fix, no one has looked back since the introduction of SATA technology. Now with SATA 6Gb/s and USB 3.0 on the horizon, you can bet that everyone is looking forward.