Filling the cavity of an HDD with helium nearly eliminates the wind turbulence that disturbs the heads. This gives HDD manufacturers design freedom to add more disks and heads to an HDD to reach a higher capacity without adversely affecting the drive’s reliability.
A sealed helium-filled drive cavity also significantly reduces the friction that occurs while disks are spinning inside the drive. Less power will be needed to operate a sealed helium-filled drive, and in the future, more disks could be added to the drive without adversely impacting power consumption.
HGST’s HelioSeal platform may be considered by some as unconventional. However, some HDD manufacturers already fill the drive cavity with helium temporarily during the HDD manufacturing process. Filling the drive cavity with helium temporarily is unexceptional. On the other hand, preventing helium from escaping from a disk drive over a prolonged period of time, over its entire useful life, is extraordinary.