What makes the drives special isn't the capacity -- a 1.5TB drive from the same company is already available -- but the density at which data is stored on each of the disk platters inside the drive. Seagate's 7200.11 drives spread the 1.5TBs across four disk platters but the new Barracuda 7200.12HD drives manage to store 1TB of data across just two platters.

That works out to a storage density, called areal density in the industry, of 329GB per square inch -- the highest yet for any hard-disk drive, according to Seagate.

The 7,200 rpm (revolution per minute) new drive is targeted at desktop personal computers, desktop RAID systems and external storage and has a Serial ATA 3G bps (bits per second) interface. Versions of the disk drive will also be available in 750GB and 500GB capacities, said Seagate.