Seagate Barracuda XT: third-generation SATA

Seagate has announced global shipment of its new flagship 3.5in. desktop hard drive, the 2TB Barracuda XT. This four-platter, 7,200rpm drive not only includes a hefty 64MB cache, but is also the first third-generation SATA product to market, with a 6 gigabits per second (6Gbps) interface. The 6Gbps SATA standard was fully ratified in May this year, and doubles the interface throughput over second-generation (3Gbps) SATA drives.

Seagate's $299 2TB Barracuda XT is the first 6Gbps SATA drive to market.

Here's the full run-down on the Barracuda XT's speeds and feeds:

Before getting over-excited about this state-of-the art desktop drive, whose list price is $299 (~£183) it's worth putting those speeds and feeds into context. For example, unless you have a drive controller that supports the new standard, you'll simply get backwards compatibility with your existing SATA (1.5Gbps) or SATA 2 (3Gbps) setup. If you're building a new high-performance desktop PC, 6Gbps SATA support is currently available on motherboards from ASUS (P7P55D) and Gigabyte (GA-P55-Extreme).

Even if you have a 6Gbps drive controller, the type of data you're retrieving from the hard drive could influence performance: to approach the drive's maximum transfer rate of 600MB/s (that's almost a CD's-worth of data a second) requires the 64MB cache to be kept supplied with the right data, otherwise performance could slow to its more stately sustained rate of 138MB/s. Fragmented drives and applications requiring lots of small, random reads are likely to tend towards the slower rate, while tasks such as video editing and media streaming are more likely to take full advantage of the Barracuda XT's architecture.

Seagate also expects key applications for its third-generation SATA drive to include small servers and workstations, desktop RAID arrays and FireWire 800- or eSATA external storage devices. To that, in due course, we can add external USB 3.0 drives.

Charles McLellan