Western Digital Expands HGST Helium Drive Lineup with 10TB Ultrastar He10
 

HGST, a Western Digital subsidiary, has been shipping hard drives sealed with helium for a couple of years now. Their helium drives have so far come in two flavors - the Ultrastar He drives using platters with traditional perpendicular magnetic recording (PMR) technology and the Ultrastar Archive Ha drives using platters with shingled magnetic recording (SMR). There are two main patented innovations behind the helium drives, HelioSeal and 7Stac. The former refers to placement of the platters in a hermetically sealed enclosure filled with helium instead of air. The latter refers to packaging of seven platters in the same 1" high form factor of traditional 3.5" drives.

http://www.anandtech.com/show/9830/w...ultrastar-he10