A helium drive is a hard disk that exploits the characteristic lightness of that gas to increase the medium’s potential speed and storage density.
Potential speed and density are increased because helium, which is less dense than air, creates less drag and turbulence. The medium’s increased density makes it possible to put seven platters in the same space required for five in conventional hard drives, reducing the weight-to-data ratio by 30%.
The smaller motor required to drive the disk consumes 23 percent less power and runs 4-5 degrees cooler, while also running more quietly. According to Western Digital (whose subsidiary HGST released the first helium drive), the storage density results in a lower cost per gigabyte (GB) and also a lower total cost of ownership (TCO).
Creating a sealed drive cost-effectively was one of the main challenges of creating helium drives. However, sealed drives make the units submersible, which simplifies liquid cooling.
Other drive manufactures are exploring alternative sealed-drive methods to increase storage density, particularly as a means of keeping mechanical storage mediums competitive with solid state drives (SSDs).