The architecture of the HGST Ultrastar He6 HDD starts with two new proprietary technologies.
HelioSeal is the patented method of hermetically sealing the HDD, trapping the Helium inside, but also keeping air out. The breathing holes commonly seen for on standard HDD's are gone, which also creates an increased resistance to humidity. Another noticeable difference is the complete absence of any fasteners, reducing weight significantly. HelioSeal technology will be utilized in a number of different uses, but for now HGST is remaining quiet on those applications. 7Stac references the new design with seven platters packed into the standard 1-inch high form factor.
Filling a drive with Helium to increase density is almost a laughable prospect until we drill down to explore how this addresses the problems with existing HDD's. Most of the major problems with HDD's boil down to air resistance. As the disk spins in a typical HDD, the platters cutting through the air inside generate turbulence. This turbulence creates intense vibration, which leads to other issues in the design of the HDD.
Turbulence can lead to the thin disk platters (constructed of glass substrate) to fly apart, necessitating thick, sturdy platters. Vibration introduces disk flutter into the equation, which increases the TMR-Error rate of the HDD. The turbulence and vibration also creates drag for the motor to overcome, thus increasing power consumption.
All of these negative effects are reduced with the removal of oxygen and the introduction of Helium. Helium has 1/7th the resistance of typical air. This cuts down drag, turbulence, and vibration, allowing the use of thinner platters. The thinner patters are constructed of normal materials, but weigh much less. This provides the double benefit of reducing air-induced drag and weight-induced drag on the motor.
With the platters occupying less space and weighing much less, the obvious solution is to pack in more heads and platters. This increases the density, but surprisingly still yields an overall reduction in power consumption and weight. The lower power consumption leads to a much lower temperature threshold for the drive, which operates cooler than typical HDD's by 4C. This reduction of heat output will lead to a tremendous reduction of power required for cooling in dense deployments.
With no fasteners, more heads, and thinner platters in the same z-height, the He6 is nothing short of revolutionary.