More on Helium HDD

Replacing regular air by helium gas inside hard disk drives is the next step to increase their capacity – not yet with better areal density – with the possibility to add more disk platters and heads into the same form factor.

HGST is the only HDD maker really pushing this new technology and we are waiting for this device filled with helium to be released this year and shipped in 4Q13. Seagate is reluctant to enter into this field and Toshiba didn’t comment the new idea.

The density of helium is seven times less than air, then reducing all mechanical frictions into the unit. Furthermore the oscillation of the rotating disks is reduced. Also there is a gain of energy of 45% in watt per terabyte or a reduced power consumption of 23%, a lower 4°C (7°F) temperature inside the box, and less noise (reduction of 0.9 bel in sleeping mode). Being a better conductor of heat than air, helium produces a more uniform temperature on the platters, protects the coating of the head and disk to lengthen the life of rotational drive, and allows a lower flying height for the heads. Less drag force acting on the spinning disk stack reduces mechanical power into the motor.

Consequently, it will be possible to push the number of platters from five – as it’s the case for current 4TB 3.5-inch HDD from HGST – to seven, and to reach 5.6TB in the same volume and then at 7TB with 1TB platters. Maybe it could be more that in the future because tracks can be placed closer together, said HGST. But don’t wait for better specs in term of access time and transfer rate to begin. We don’t know if there is a possibility to push the rotation speed of the 3.5-inch disks from 7,200rpm to 10,000rpm, today an impossible feat because of the resulting heat and vibration. Only real advantage of helium devices being capacity, the main usage will be for cold storage, not mission-critical applications.

Analyst firm IHS predicted that the market for these helium-filled units will climb to more than 100 million units in 2016 if high production costs are brought down.

But helium drives could be more expensive because the gas, a non-renewable resource, is more expensive than free air. Furthermore it is expected to be in short supply in the future. Also the U.S. Congress in 1996 voted to sell off the nation’s helium reserve by the year 2015.

The new disk structure will also have costs. Here is the abstract of a patent from HGST "Hermetically sealing a hard disk drive": "A hard disk drive comprising: an internal base plate comprising a porous material and configured for attachment of internal components of said hard disk drive; an external hermetic base plate comprising a non-porous material and configured to hermetically seal said hard disk drive, wherein said internal base plate is adjacent to a first side of said external hermetic base plate; an external attachment base plate comprising fastening features, wherein said external attachment base plate is adjacent to a second side of said external hermetic base plate opposite said first side of said external hermetic base plate, wherein said external attachment base plate comprises a bottom surface that is coplanar with a bottom surface of said external hermetic base plate, and wherein said external attachment base plate comprises an external attachment feature; and an external hermetic cover hermetically sealed to said external hermetic base plate, wherein said internal base plate and said internal components of said hard disk drive are hermetically sealed within said hard disk drive."

Concerning these helium HDDs, there are also two main questions. How the gas is filled? How to know and what happens if there is a leak during the usage of the unit?

Jerry Kagele, SVP of WW sales at HGST, didn’t want to say too much concerning these points during a press conference in Paris, but we have understood that the helium will be introduced into the HDD case at the end of the assembly process.

It’s not easy to keep helium in a sealed environment and the drive must remain perfectly sealed. When it will be performing, a leak will be automatically detected at the head level because the pressure inside the unit will be different. In this case, it will be better to stop immediately to use the device. But Kagele said that, after running helium drives for four years in lab, finally they are more robust and the MTBF will probably be higher than current HDDs.

Read also:
HGST HDD With Helium Inside (Replacing Air) in 2013
Enabling seven disk platters into 3.5-inch drive for 5.6TB
Helium-Filled HDDs Could Lift WD Above Competition in Enterprise Market
According to IHS iSuppli research