HGST's new ground-breaking Helium HDD has appeared on Amazon in the US where it is on sale for a stonking $727 (around £450 excluding taxes or delivery).

That is far more expensive, even on a per GB basis, compared to 4TB hard disk drives whose prices have been slowly coming down. The 6TB drive initially cost $800 when it was first listed on Amazon.

The device, known as the A7K 6000 or HUS726060ALA640, packs 6TB on seven platters, has a spinning speed of 7,200RPM, 64MB of cache and a SATA interface.

Capacity at a premium price

Using helium, a rare gas and the second lightest element after hydrogen, means that the drive is cooler, less noisy and uses less power than smaller capacity drive.

The Ultrastar He6 was introduced late last year and is expected to be popular with data centres as it packs 50 per cent more capacity per drive.

Note that formatting the hard drive would probably bring down the capacity to around 5.5TB. 4TB HDDs currently cost around £120 or 30p per GB, less than half what the new drive costs.

The technology is expected to trickle down to the smaller 2.5-inch form factor where it could lead to the introduction of a 2TB HDD.